javagit/src/main/java/edu/nyu/cs/javagit/utilities/CheckUtilities.java
public static void validateArgumentRefType(Ref name, Ref.RefType type, String variableName) {
    checkNullArgument(name, variableName);
    if (name.getRefType() != type) {
      throw new IllegalArgumentException(ExceptionMessageMap.getMessage("100000")
          + "  { variableName=[" + variableName + "] }");
    }
  }
public static void validateArgumentRefType(Ref name, Ref.RefType type, String variableName) {
    checkNullArgument(name, variableName);
    if (name.getRefType() != type) {
      throw new IllegalArgumentException(ExceptionMessageMap.getMessage("100000")
          + "  { variableName=[" + variableName + "] }");
    }
  }
Checks a <code>Ref</code> argument to make sure that it is of given <code>refType</code> type.
If not <code>IllegalArgumentException</code> is thrown.

@param name
The argument to check.
@param type
The <code>refType</code> to check against.
@param variableName
The name of the variable being checked; for use in exception messages.