@Override
    public IndexBuffer put(int value) {
        throw new UnsupportedOperationException("Does not represent index buffer");
    }
IndexBuffer implementation that generates vertex indices sequentially
based on a specific Mesh {@link Mode}.
The generated indices are as if the mesh is in the given mode
but contains no index buffer, thus this implementation will
return the indices if the index buffer was there and contained sequential
triangles.
Example:
<ul>
<li>{@link Mode#Triangles}: 0, 1, 2 | 3, 4, 5 | 6, 7, 8 | ...</li>
<li>{@link Mode#TriangleStrip}: 0, 1, 2 | 2, 1, 3 | 2, 3, 4 | ...</li>
<li>{@link Mode#TriangleFan}: 0, 1, 2 | 0, 2, 3 | 0, 3, 4 | ...</li>
</ul>

@author Kirill Vainer
jme3-core/src/main/java/com/jme3/scene/mesh/VirtualIndexBuffer.java