Function validateMethodOverride

lib/assets/react-source/development/react.js:29621–29647

(isAlreadyDefined, name)

	  }

	  function validateMethodOverride(isAlreadyDefined, name) {
	    var specPolicy = ReactClassInterface.hasOwnProperty(name)
	      ? ReactClassInterface[name]
	      : null;

	    // Disallow overriding of base class methods unless explicitly allowed.
	    if (ReactClassMixin.hasOwnProperty(name)) {
	      _invariant(
	        specPolicy === 'OVERRIDE_BASE',
	        'ReactClassInterface: You are attempting to override ' +
	          '`%s` from your class specification. Ensure that your method names ' +
	          'do not overlap with React methods.',
	        name
	      );
	    }

	    // Disallow defining methods more than once unless explicitly allowed.
	    if (isAlreadyDefined) {
	      _invariant(
	        specPolicy === 'DEFINE_MANY' || specPolicy === 'DEFINE_MANY_MERGED',
	        'ReactClassInterface: You are attempting to define ' +
	          '`%s` on your component more than once. This conflict may be due ' +
	          'to a mixin.',
	        name
	      );
	    }
	  }

	  /**
	   * Mixin helper which handles policy validation and reserved