text: const Base = require('./base');
  const isNumber = require('@antv/util/lib/type/isNumber');
  
  class Identity extends Base {
  
    _initDefaultCfg() {
      super._initDefaultCfg();
      this.isIdentity = true;
      this.type = 'identity';
      /**
       * 常量值
       * @type {*}
       */
      this.value = null;
    }
  
    /**
     * @override
     */
    getText() {
      return this.value.toString();
    }
  
    /**
     * @override
     */
    scale(value) {
      if (this.value !== value && isNumber(value)) {
        return value;
      }
      return this.range[0];
    }
  
    /**
     * @override
     */
    invert() {
      return this.value;
    }
  }
  
  Base.Identity = Identity;
  module.exports = Identity;
  