class MetadataTreeNode {
    ArtifactMetadata md; // this node

    MetadataTreeNode parent; // papa

    /** default # of children. Used for tree creation optimization only */
    int nChildren = 8;

    MetadataTreeNode[] children; // of cause

    public int getNChildren() {
        return nChildren;
    }

    public void setNChildren(int children) {
        nChildren = children;
    }

    // ------------------------------------------------------------------------
    public MetadataTreeNode() {}
    // ------------------------------------------------------------------------
    public MetadataTreeNode(ArtifactMetadata md, MetadataTreeNode parent, boolean resolved, ArtifactScopeEnum scope) {
        if (md != null) {
            md.setArtifactScope(ArtifactScopeEnum.checkScope(scope));
            md.setResolved(resolved);
        }

        this.md = md;
        this.parent = parent;
    }
    // ------------------------------------------------------------------------
    public MetadataTreeNode(Artifact af, MetadataTreeNode parent, boolean resolved, ArtifactScopeEnum scope) {
        this(new ArtifactMetadata(af), parent, resolved, scope);
    }

    // ------------------------------------------------------------------------
    public void addChild(int index, MetadataTreeNode kid) {<FILL_FUNCTION_BODY>}

    // ------------------------------------------------------------------
    @Override
    public String toString() {
        return md == null ? "no metadata" : md.toString();
    }

    // ------------------------------------------------------------------
    public String graphHash() throws MetadataResolutionException {
        if (md == null) {
            throw new MetadataResolutionException(
                    "treenode without metadata, parent: " + (parent == null ? "null" : parent.toString()));
        }

        return md.groupId + ":" + md.artifactId;
    }

    // ------------------------------------------------------------------------
    public boolean hasChildren() {
        return children != null;
    }
    // ------------------------------------------------------------------------
    public ArtifactMetadata getMd() {
        return md;
    }

    public void setMd(ArtifactMetadata md) {
        this.md = md;
    }

    public MetadataTreeNode getParent() {
        return parent;
    }

    public void setParent(MetadataTreeNode parent) {
        this.parent = parent;
    }

    public MetadataTreeNode[] getChildren() {
        return children;
    }

    public void setChildren(MetadataTreeNode[] children) {
        this.children = children;
    }
    // ------------------------------------------------------------------------
    // ------------------------------------------------------------------------

}

        if (kid == null) {
            return;
        }

        if (children == null) {
            children = new MetadataTreeNode[nChildren];
        }

        children[index % nChildren] = kid;
    
<no_super_class>