code: function getParameterMap(parameters) {
          if (parameters == null) {
              return {};
          }
          if (typeof parameters != "object") {
              return OAuth.getParameterMap(OAuth.decodeForm(parameters + ""));
          }
          if (parameters instanceof Array) {
              var map = {};
              for (var p = 0; p < parameters.length; ++p) {
                  var key = parameters[p][0];
                  if (map[key] === undefined) { // first value wins
                      map[key] = parameters[p][1];
                  }
              }
              return map;
          }
          return parameters;
      }
docs: Convert the given parameters to a map from name to value.