code: private boolean isDerived(JavaClass fqCls, FQMethod key) {
          try {
              for (JavaClass infCls : fqCls.getInterfaces()) {
                  for (Method infMethod : infCls.getMethods()) {
                      if (key.getMethodName().equals(infMethod.getName())) {
                          if (infMethod.getGenericSignature() != null) {
                              if (SignatureUtils.compareGenericSignature(infMethod.getGenericSignature(), key.getSignature())) {
                                  return true;
                              }
                          } else if (infMethod.getSignature().equals(key.getSignature())) {
                              return true;
                          }
                      }
                  }
              }
  
              JavaClass superClass = fqCls.getSuperClass();
              if ((superClass == null) || Values.DOTTED_JAVA_LANG_OBJECT.equals(superClass.getClassName())) {
                  return false;
              }
  
              for (Method superMethod : superClass.getMethods()) {
                  if (key.getMethodName().equals(superMethod.getName())) {
                      if (superMethod.getGenericSignature() != null) {
                          if (SignatureUtils.compareGenericSignature(superMethod.getGenericSignature(), key.getSignature())) {
                              return true;
                          }
                      } else if (superMethod.getSignature().equals(key.getSignature())) {
                          return true;
                      }
                  }
              }
  
              return isDerived(superClass, key);
          } catch (ClassNotFoundException cnfe) {
              bugReporter.reportMissingClass(cnfe);
              return true;
          }
      }
docs: looks to see if this method described by key is derived from a superclass or interface
  
  @param fqCls
  the class that the method is defined in
  @param key
  the information about the method
  @return whether this method derives from something or not