@Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final OgreMeshKey other = (OgreMeshKey) obj;
        if (!super.equals(other)) {
            return false;
        }
        if (this.materialList != other.materialList && (this.materialList == null || !this.materialList.equals(other.materialList))) {
            return false;
        }
        if ((this.materialName == null) ? (other.materialName != null) : !this.materialName.equals(other.materialName)) {
            return false;
        }
        return true;
    }
OgreMeshKey is used to load Ogre3D mesh.xml models with a specific
material file or list. This allows customizing from where the materials
are retrieved, instead of loading the material file as the same
name as the model (the default).

@author Kirill Vainer
jme3-plugins/src/ogre/java/com/jme3/scene/plugins/ogre/OgreMeshKey.java