code: @Nonnull
      public BugInstance addCalledMethod(String className, String methodName, String methodSig, boolean isStatic) {
          return addMethod(MethodAnnotation.fromCalledMethod(className, methodName, methodSig, isStatic)).describe(
                  MethodAnnotation.METHOD_CALLED);
      }
docs: Add a method annotation.
  
  @param className
  name of class containing called method
  @param methodName
  name of called method
  @param methodSig
  signature of called method
  @param isStatic
  true if called method is static, false if not
  @return this object