code: function _verifySignature(signature, value) {
          if (value === undefined) {
              console.assert(signature.optional === true, "Missing argument: " + signature.name);
          }
          return true;
      }
docs: user agent string Check a parameter value against the given signature
  This only checks for optional parameters, not types
  Type checking is complex because of $ref and done on the remote end anyways
  @param {signature}
  @param {value}