code: function isEmpty( value ) {
    return isUndefined( value ) ||
           value === null ||
           isString( value ) &&
           value.length <= 0 ||
           ( /^\s*$/ ).test( value );
  }
docs: TODO Fix complexity issue /* eslint-disable complexity, no-mixed-operators 
  @name isEmpty
  @kind function
  
  @description
  Determines if a reference is empty.
  
  @param {*} value Reference to check.
  @returns {boolean} True if `value` is empty.