code: function(id) {
          return this.getFields().findBy(function(f) {
              return f.id === id || f.getName() === id;
          });
      }
docs: Find a specific {@link Ext.form.field.Field} in this form by id or name.
  @param {String} id The value to search for (specify either a {@link Ext.Component#id id} or
  {@link Ext.form.field.Field#getName name or hiddenName}).
  @return {Ext.form.field.Field} The first matching field, or `null` if none was found.