code: function getForInVariableSymbol(node) {
              var initializer = node.initializer;
              if (initializer.kind === 219 /* VariableDeclarationList */) {
                  var variable = initializer.declarations[0];
                  if (variable && !ts.isBindingPattern(variable.name)) {
                      return getSymbolOfNode(variable);
                  }
              }
              else if (initializer.kind === 69 /* Identifier */) {
                  return getResolvedSymbol(initializer);
              }
              return undefined;
          }
docs: Return the symbol of the for-in variable declared or referenced by the given for-in statement.