code: function(payload) {
      var self = this;
      if (this.options.compressor) {
        return this.options.compressor;
      }
  
      payload = payload || JSON.stringify(this.toJSON());
      if (!this.options.force_compress && payload.length < this.options.MAX_GET_SIZE) {
        return function(data, level, callback) {
          callback("config=" + encodeURIComponent(data));
        };
      }
  
      return function(data, level, callback) {
        data = JSON.stringify({ config: data });
        LZMA.compress(data, level, function(encoded) {
          callback("lzma=" + encodeURIComponent(cdb.core.util.array2hex(encoded)));
        });
      };
  
    }
docs: returns the compressor depending on the size of the layer