Function onlyChild

lib/assets/react-source/development/react.js:1640–1648

* Returns the first child in a collection of children and verifies that there * is only one child in the collection. * * See https://reactjs.org/docs/react-api.html#reactchildrenonly * * The current implementation of this function assumes that a single child gets * passed without a wrapp

(children)

	function onlyChild(children) {
	  if (!isValidElement(children)) {
	    {
	      throw Error( "React.Children.only expected to receive a single React element child." );
	    }
	  }

	  return children;
	}

	function createContext(defaultValue, calculateChangedBits) {
	  if (calculateChangedBits === undefined) {