code: function $split(params) {
      if (typeof params === 'string') {
          return params.split(/\s+/);
      }
      if (
          Array.isArray(params) &&
          (params.length === 2 || params.length === 3) &&
          typeof params[0] === 'string' &&
          typeof params[1] === 'string' &&
          (params[3] == null || typeof params[3] === 'number')
      ) {
          return params[0].split(params[1], params[2]);
      }
      throw new Error(
          '$split expects an array of two string elements with an additional number element'
      );
  }
docs: Split input string into an array
  
  @param {string|[string, string]|[string, string, number]} params
  @returns {number[]}