Get the link var corresponding to the specified parent and child position.

@param parent The parent word position (1-indexed), or 0 to indicate the wall node.
@param child The child word position (1-indexed).
@return The link variable.
189033
public LinkVar getLinkVar1Idx(int parent, int child) {
        if (parent == 0) {
            return rootVars[child-1];
        } else {
            return childVars[parent-1][child-1];
        }
    }
552944
@Override
    public Node getParentNode(String parentNodeId)
    {
        NodeLink link = new NodeLink(parentNodeId, getNodeId());

        if (this.parents == null)
        {
            return null;
        }
        else
        {
            return this.parents.get(link);
        }
    }
397059
@Override
    public Node getChildNode(String childNodeId)
    {
        NodeLink link = new NodeLink(getNodeId(), childNodeId);

        if (this.children == null)
        {
            return null;
        }
        else
        {
            return this.children.get(link);
        }
    }
1249720
public Option<V> getSingle(final K parent) {
        return Option.of(this.singletons.get(parent));
    }
1363405
function getThingPosition(user, parentThing, childThing) {

	if (!childThing)
		throw new utils.ErrorCustom(httpStatusCodes.INTERNAL_SERVER_ERROR, "Child Thing can't be null", 29);

	// If User is equal to null as it may be anonymous or is a SuperAdministrator who has no relationship with Thing
	if (!user)
		return null;

	let userId = user._id;
	let parentThingId = parentThing ? parentThing._id : null;

	return childThing.parentsThingsIds.find(p => p.userId == userId && p.parentThingId == parentThingId);
}
1180733
protected void setParent(Object parent, Object child) {
        getProxyBuilder().getCurrentFactory().setParent(getProxyBuilder().getChildBuilder(), parent, child);
        Factory parentFactory = getProxyBuilder().getParentFactory();
        if (parentFactory != null) {
            parentFactory.setChild(getProxyBuilder().getCurrentBuilder(), parent, child);
        }
    }
3273
function getScrollParent(parent, child) {
  let element = child;
  let scrollTop = 0;

  while (element && element !== parent) {
    element = element.parentNode;
    scrollTop += element.scrollTop;
  }
  return scrollTop;
}
1196687
public long getChildItemId(View child) {
        if (mAdapter == null || !mAdapter.hasStableIds()) {
            return NO_ID;
        }
        final ViewHolder holder = getChildViewHolderInt(child);
        return holder != null ? holder.getItemId() : NO_ID;
    }
735086
public static Element getChild(Element parent, String childName) {
		NodeList nodes = parent.getChildNodes();
		for (int i = 0; i < nodes.getLength(); ++i) {
			Node node = nodes.item(i);
			if ((node instanceof Element) && node.getNodeName().equals(childName))
				return (Element)node;
		}
		return null;
	}
184026
@Pure
	protected final Graph<ST, PT> getParentGraph() {
		return this.parentGraph == null ? null : this.parentGraph.get();
	}
156699
@Unstable
    public long indexOf(Block child)
    {
        CounterBlockMatcher counter = new CounterBlockMatcher(child);

        Block found = getFirstBlock(counter, Axes.ANCESTOR_OR_SELF);

        return found != null ? counter.getCount() : -1;
    }
530000
function getParentNode(node) {
  return genericPropertyGet(
      Methods.PARENT_NODE_GETTER, node, 'parentNode', function(parentNode) {
        // We need to ensure that parentNode is returning the actual parent node
        // and not a child node that happens to have a name of "parentNode".
        // We check that the node returned by parentNode is itself not named
        // "parentNode" - this could happen legitimately but on IE we have no
        // better means of avoiding the pitfall.
        return !(
            parentNode && typeof parentNode.name == 'string' &&
            parentNode.name && parentNode.name.toLowerCase() == 'parentnode');
      });
}
433570
public static String child(String node) {
        final int index = node.lastIndexOf('/');
        if (index < 0 || index == node.length() - 1)
            return null;
        return node.substring(index + 1, node.length());
    }
765684
public int getTabIndex(Element child) {

        int index = 0;
        for (Widget tab : m_tabPanel) {
            if (tab.getElement().isOrHasChild(child)) {
                return index;
            }
            index++;
        }
        return -1;
    }
18394
public EJSHome getTargetHome(String child)
    {
        EJSHome targetHome = null;
        HomeRecord targetHomeRecord = childBeans.get(child);
        if (targetHomeRecord == null) {
            //try recursively
            Enumeration<HomeRecord> children = childBeans.elements();
            while (children.hasMoreElements()) {
                HomeRecord childHomeRecord = children.nextElement();
                targetHome = childHomeRecord.getTargetHome(child);
                if (targetHome != null)
                    break;
            }
        }
        // Get the EJSHome from the homeRecord.  If the home has not been
        // initialized yet, call HomeOfHomes.getHome() to trigger it.
        if (targetHomeRecord != null) {
            targetHome = targetHomeRecord.getHomeAndInitialize(); // d648522
        }
        return targetHome;
    }
410950
public IPRangeNode findRange(IPRangeNode child) {

	for (IPRangeNode c: this.list) {

	    IPRangeNode result = c.findRange(child);

	    if (result != null) return result;
	}

	return null;
    }
798575
public static Element getChild( Element root, String name )
    {
        if( null == root )
        {
            return null;
        }
        NodeList list = root.getElementsByTagName( name );
        int n = list.getLength();
        if( n < 1 )
        {
            return null;
        }
        return (Element) list.item( 0 );
    }