title: java.lang.IllegalStateException:Failed to transform class with name UnitySaveFCPort$PortMetric.Reason:[source error]a constructor cannot be static
body: <p>I am new to powermock. I am trying to mock a private method and run the testcase.
  But I am getting following error :</p>
  
  <pre><code>java.lang.IllegalStateException: Failed to transform class with name UnitySaveFCPortPerfByInterval$PortMetric. Reason: [source error] a constructor cannot be static
  
      at org.powermock.core.classloader.MockClassLoader.loadMockClass(MockClassLoader.java:283)
      at org.powermock.core.classloader.MockClassLoader.loadModifiedClass(MockClassLoader.java:192)
      at org.powermock.core.classloader.DeferSupportingClassLoader.loadClass(DeferSupportingClassLoader.java:71)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
      at java.lang.Class.getDeclaredMethods0(Native Method)
      at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
      at java.lang.Class.getDeclaredMethods(Class.java:1975)
      at org.codehaus.groovy.reflection.CachedClass$3$1.run(CachedClass.java:85)
      at java.security.AccessController.doPrivileged(Native Method)
      at org.codehaus.groovy.reflection.CachedClass$3.initValue(CachedClass.java:82)
      at org.codehaus.groovy.reflection.CachedClass$3.initValue(CachedClass.java:80)
      at org.codehaus.groovy.util.LazyReference.getLocked(LazyReference.java:46)
      at org.codehaus.groovy.util.LazyReference.get(LazyReference.java:33)
      at org.codehaus.groovy.reflection.CachedClass.getMethods(CachedClass.java:251)
      at groovy.lang.MetaClassImpl.populateMethods(MetaClassImpl.java:390)
      at groovy.lang.MetaClassImpl.fillMethodIndex(MetaClassImpl.java:340)
      at groovy.lang.MetaClassImpl.initialize(MetaClassImpl.java:3224)
      at org.codehaus.groovy.reflection.ClassInfo.getMetaClassUnderLock(ClassInfo.java:222)
      at org.codehaus.groovy.reflection.ClassInfo.getMetaClass(ClassInfo.java:253)
      at org.codehaus.groovy.runtime.metaclass.MetaClassRegistryImpl.getMetaClass(MetaClassRegistryImpl.java:255)
      at org.codehaus.groovy.runtime.InvokerHelper.getMetaClass(InvokerHelper.java:859)
      at org.codehaus.groovy.runtime.callsite.CallSiteArray.createCallConstructorSite(CallSiteArray.java:84)
      at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallConstructor(CallSiteArray.java:57)
      at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:182)
      at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:190)
      at TestUnitySaveFCPortPerfByInterval.testFCPortPerfByInterval(TestUnitySaveFCPortPerfByInterval.groovy:47)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:68)
      at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:310)
      at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:89)
      at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:97)
      at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:294)
      at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:127)
      at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
      at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:282)
      at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:87)
      at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:50)
      at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:207)
      at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:146)
      at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:120)
      at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
      at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
      at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:122)
      at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:106)
      at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)
      at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
      at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
      at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
      at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
      at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
      at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
  Caused by: javassist.CannotCompileException: [source error] a constructor cannot be static
      at javassist.expr.MethodCall.replace(MethodCall.java:241)
      at org.powermock.core.transformers.impl.AbstractMainMockTransformer$PowerMockExpressionEditor.edit(AbstractMainMockTransformer.java:370)
      at javassist.expr.ExprEditor.loopBody(ExprEditor.java:220)
      at javassist.expr.ExprEditor.doit(ExprEditor.java:91)
      at javassist.CtClassType.instrument(CtClassType.java:1437)
      at org.powermock.core.transformers.impl.ClassMockTransformer.transformMockClass(ClassMockTransformer.java:65)
      at org.powermock.core.transformers.impl.AbstractMainMockTransformer.transform(AbstractMainMockTransformer.java:247)
      at org.powermock.core.classloader.MockClassLoader.loadMockClass(MockClassLoader.java:264)
      ... 53 more
  Caused by: compile error: a constructor cannot be static
      at javassist.compiler.MemberCodeGen.atCallExpr(MemberCodeGen.java:474)
      at javassist.compiler.JvstCodeGen.atCallExpr(JvstCodeGen.java:244)
      at javassist.compiler.ast.CallExpr.accept(CallExpr.java:46)
      at javassist.compiler.CodeGen.atStmnt(CodeGen.java:338)
      at javassist.compiler.ast.Stmnt.accept(Stmnt.java:50)
      at javassist.compiler.CodeGen.atStmnt(CodeGen.java:351)
      at javassist.compiler.ast.Stmnt.accept(Stmnt.java:50)
      at javassist.compiler.CodeGen.atIfStmnt(CodeGen.java:398)
      at javassist.compiler.CodeGen.atStmnt(CodeGen.java:355)
      at javassist.compiler.ast.Stmnt.accept(Stmnt.java:50)
      at javassist.compiler.CodeGen.atStmnt(CodeGen.java:351)
      at javassist.compiler.ast.Stmnt.accept(Stmnt.java:50)
      at javassist.compiler.Javac.compileStmnt(Javac.java:569)
      at javassist.expr.MethodCall.replace(MethodCall.java:235)
      ... 60 more
  </code></pre>
  
  <p>I have been mocking private methods for other classes, everything works fine.
  The only difference between other classes and the class for which test case is failing is it has enum called :</p>
  
  <pre><code>private enum PortMetric {
          READ_IOS, WRITE_IOS, KBYTES_READ, KBYTES_WRITTEN
      }
  </code></pre>