code: public static List<Method> retrieveMethodList(final Class<?> cls, final String methodName) {
          final List<Method> methodList = new ArrayList<>();
          final String camelCasedMethodName = underscoreToCamelCase(methodName);
          for (final Method m : cls.getMethods()) {
              if (m.getName().equals(camelCasedMethodName) || m.getName().equals(methodName)) {
                  methodList.add(m);
              }
          }
          return methodList;
      }
docs: Check if the given method exists in the given class.
  
  @param cls the class to search into
  @param methodName the name of the method to check (camelCased or in upper case with underscore separator)
  
  @return true if the method exists