docs: function checkStageStepId(method, s, id) {
          var char0;
          if ('string' !== typeof id) {
              throw new TypeError('Stager.' + method + ': ' + s + '.id must ' +
                                  'be string. Found: ' + id);
          }
          if (id.trim() === '') {
              throw new TypeError('Stager.' + method + ': ' + s + '.id cannot ' +
                                  'be an empty string.');
          }
          char0 = id.charAt(0);
          if (char0 === '.') {
              throw new Error('Stager.' + method + ': ' + s + '.id cannot ' +
                              'begin with a dot. Found: ' + id);
          }
          if (id.lastIndexOf('.') !== -1) {
              console.log('*** deprecated naming! Stager.' + method + ': ' +
                          s + '.id contains dots. Game will run, but will fail ' +
                          'to normalize ' + s + 's. Found: ' + id + ' ***');
          }
          if (/^\d+$/.test(char0)) {
              console.log('*** deprecated naming! Stager.' + method + ': ' + s +
                          '.id begins with a number. Game will run, but will ' +
                          'fail to normalize ' + s + 's. Found: ' + id + ' ***');
          }
      }