@Nullable
	public synchronized WorkspaceTreeNode getFirstChild() {
		// Get first child, regardless of the current filter.
		var children = getSourceChildren();
		return children.isEmpty()
				? null : children.getFirst() instanceof WorkspaceTreeNode node
				? node : null;
	}
@return First child tree node. {@code null} if no child is found.
recaf-ui/src/main/java/software/coley/recaf/ui/control/tree/WorkspaceTreeNode.java