code: @Nullable
      private static Method findMethod(JavaClass cls, String methodName, String methodSig) {
          Method[] methods = cls.getMethods();
          for (Method method : methods) {
              if (method.getName().equals(methodName) && method.getSignature().equals(methodSig)) {
                  return method;
              }
          }
          return null;
      }
docs: finds a method that matches the name and signature in the given class
  
  @param cls        the class to look in
  @param methodName the name to look for
  @param methodSig  the signature to look for
  
  @return the method or null