function traverseAllChildrenImpl(children, nameSoFar, callback, traverseContext) {
	  var type = typeof children;

	  if (type === 'undefined' || type === 'boolean') {
	    // All of the above are perceived as null.
	    children = null;
	  }

	  if (children === null || type === 'string' || type === 'number' ||
	  // The following is inlined from ReactElement. This means we can optimize
	  // some checks. React Fiber also inlines this logic for similar purposes.
	  type === 'object' && children.$$typeof === REACT_ELEMENT_TYPE) {
	    callback(traverseContext, children,
	    // If it's the only child, treat the name as if it was wrapped in an array
	    // so that it's consistent if the number of children grows.
	    nameSoFar === '' ? SEPARATOR + getComponentKey(children, 0) : nameSoFar);
	    return 1;
	  }

	  var child;
	  var nextName;
	  var subtreeCount = 0; // Count of children found in the current subtree.
	  var nextNamePrefix = nameSoFar === '' ? SEPARATOR : nameSoFar + SUBSEPARATOR;

	  if (Array.isArray(children)) {
	    for (var i = 0; i < children.length; i++) {
	      child = children[i];
	      nextName = nextNamePrefix + getComponentKey(child, i);
	      subtreeCount += traverseAllChildrenImpl(child, nextName, callback, traverseContext);
	    }
	  } else {
	    var iteratorFn = getIteratorFn(children);
	    if (iteratorFn) {
	      var iterator = iteratorFn.call(children);
	      var step;
	      if (iteratorFn !== children.entries) {
	        var ii = 0;
	        while (!(step = iterator.next()).done) {
	          child = step.value;
	          nextName = nextNamePrefix + getComponentKey(child, ii++);
	          subtreeCount += traverseAllChildrenImpl(child, nextName, callback, traverseContext);
	        }
	      } else {
	        if (process.env.NODE_ENV !== 'production') {
	          var mapsAsChildrenAddendum = '';
	          if (ReactCurrentOwner.current) {
	            var mapsAsChildrenOwnerName = ReactCurrentOwner.current.getName();
	            if (mapsAsChildrenOwnerName) {
	              mapsAsChildrenAddendum = ' Check the render method of `' + mapsAsChildrenOwnerName + '`.';
	            }
	          }
	          process.env.NODE_ENV !== 'production' ? warning(didWarnAboutMaps, 'Using Maps as children is not yet fully supported. It is an ' + 'experimental feature that might be removed. Convert it to a ' + 'sequence / iterable of keyed ReactElements instead.%s', mapsAsChildrenAddendum) : void 0;
	          didWarnAboutMaps = true;
	        }
	        // Iterator will provide entry [k,v] tuples rather than values.
	        while (!(step = iterator.next()).done) {
	          var entry = step.value;
	          if (entry) {
	            child = entry[1];
	            nextName = nextNamePrefix + KeyEscapeUtils.escape(entry[0]) + SUBSEPARATOR + getComponentKey(child, 0);
	            subtreeCount += traverseAllChildrenImpl(child, nextName, callback, traverseContext);
	          }
	        }
	      }
	    } else if (type === 'object') {
	      var addendum = '';
	      if (process.env.NODE_ENV !== 'production') {
	        addendum = ' If you meant to render a collection of children, use an array ' + 'instead or wrap the object using createFragment(object) from the ' + 'React add-ons.';
	        if (children._isReactElement) {
	          addendum = ' It looks like you\'re using an element created by a different ' + 'version of React. Make sure to use only one copy of React.';
	        }
	        if (ReactCurrentOwner.current) {
	          var name = ReactCurrentOwner.current.getName();
	          if (name) {
	            addendum += ' Check the render method of `' + name + '`.';
	          }
	        }
	      }
	      var childrenString = String(children);
	       true ? process.env.NODE_ENV !== 'production' ? invariant(false, 'Objects are not valid as a React child (found: %s).%s', childrenString === '[object Object]' ? 'object with keys {' + Object.keys(children).join(', ') + '}' : childrenString, addendum) : _prodInvariant('31', childrenString === '[object Object]' ? 'object with keys {' + Object.keys(children).join(', ') + '}' : childrenString, addendum) : void 0;
	    }
	  }

	  return subtreeCount;
	}
@param {?*} children Children tree container.
@param {!string} nameSoFar Name of the key path so far.
@param {!function} callback Callback to invoke with each child found.
@param {?*} traverseContext Used to pass information throughout the traversal
process.
@return {!number} The number of children in this subtree.