code: function createCompilerDiagnosticForInvalidCustomType(opt) {
          var namesOfType = [];
          for (var key in opt.type) {
              namesOfType.push(" '" + key + "'");
          }
          return ts.createCompilerDiagnostic(ts.Diagnostics.Argument_for_0_option_must_be_Colon_1, "--" + opt.name, namesOfType);
      }
docs: /* @internal