docs: function (s) {
              var ret, m;
              if ((m = s.match(this._static.COLUMN_REF_RE1)) !== null) {
                  ret = m.slice(1);
              }
              else if ((m = s.match(this._static.COLUMN_REF_RE2)) !== null) {
                  ret = [null, m[1], m[2]];
              }
              else if ((m = s.match(this._static.COLUMN_REF_RE3)) !== null) {
                  ret = [m[1], m[2], null];
              }
              else {
                  ret = [null, s, null];
              }
              return ret;
          }