bootstrap/src/main/java/com/streamsets/pipeline/BootstrapMain.java
public static void premain(String args, Instrumentation instrumentation) {
    if (BootstrapMain.instrumentation == null) {
      BootstrapMain.instrumentation = instrumentation;
    } else {
      throw new IllegalStateException("Premain method cannot be called twice (" + BootstrapMain.instrumentation + ")");
    }
  }
public static void premain(String args, Instrumentation instrumentation) {
    if (BootstrapMain.instrumentation == null) {
      BootstrapMain.instrumentation = instrumentation;
    } else {
      throw new IllegalStateException("Premain method cannot be called twice (" + BootstrapMain.instrumentation + ")");
    }
  }
Visible due to JVM requirements only