dist/react-tappable.js
function getPooledWarningPropertyDefinition(propName, getVal) {
  var isFunction = typeof getVal === 'function';
  return {
    configurable: true,
    set: set,
    get: get
  };

  function set(val) {
    var action = isFunction ? 'setting the method' : 'setting the property';
    warn(action, 'This is effectively a no-op');
    return val;
  }

  function get() {
    var action = isFunction ? 'accessing the method' : 'accessing the property';
    var result = isFunction ? 'This is a no-op function' : 'This is set to null';
    warn(action, result);
    return getVal;
  }

  function warn(action, result) {
    var warningCondition = false;
    warning(warningCondition, "This synthetic event is reused for performance reasons. If you're seeing this, " + "you're %s `%s` on a released/nullified synthetic event. %s. " + 'If you must keep the original synthetic event around, use event.persist(). ' + 'See https://fb.me/react-event-pooling for more information.', action, propName, result);
  }
}
function getPooledWarningPropertyDefinition(propName, getVal) {
  var isFunction = typeof getVal === 'function';
  return {
    configurable: true,
    set: set,
    get: get
  };

  function set(val) {
    var action = isFunction ? 'setting the method' : 'setting the property';
    warn(action, 'This is effectively a no-op');
    return val;
  }

  function get() {
    var action = isFunction ? 'accessing the method' : 'accessing the property';
    var result = isFunction ? 'This is a no-op function' : 'This is set to null';
    warn(action, result);
    return getVal;
  }

  function warn(action, result) {
    var warningCondition = false;
    warning(warningCondition, "This synthetic event is reused for performance reasons. If you're seeing this, " + "you're %s `%s` on a released/nullified synthetic event. %s. " + 'If you must keep the original synthetic event around, use event.persist(). ' + 'See https://fb.me/react-event-pooling for more information.', action, propName, result);
  }
}
function getPooledWarningPropertyDefinition ( propName , getVal ) { var isFunction = typeof getVal === 'function' ; return { configurable : true , set : set , get : get } ; function set ( val ) { var action = isFunction ? 'setting the method' : 'setting the property' ; warn ( action , 'This is effectively a no-op' ) ; return val ; } function get ( ) { var action = isFunction ? 'accessing the method' : 'accessing the property' ; var result = isFunction ? 'This is a no-op function' : 'This is set to null' ; warn ( action , result ) ; return getVal ; } function warn ( action , result ) { var warningCondition = false ; warning ( warningCondition , "This synthetic event is reused for performance reasons. If you're seeing this, " + "you're %s `%s` on a released/nullified synthetic event. %s. " + 'If you must keep the original synthetic event around, use event.persist(). ' + 'See https://fb.me/react-event-pooling for more information.' , action , propName , result ) ; } }
Helper to nullify syntheticEvent instance properties when destructing

@param {String} propName
@param {?object} getVal
@return {object} defineProperty object
Helper to nullify syntheticEvent instance properties when destructing