Removed unused method
Removed unused method

Fixed -Wunused-member-function warning, the only
such warning in the codebase.

Change-Id: I8c2fe36cd1dc07475711cb454d2327b6b7a9c50b

keithroe/vtkoptix,ashray/VTK-EVM,sankhesh/VTK,jmerkow/VTK,msmolens/VTK,sumedhasingla/VTK,hendradarwin/VTK,sankhesh/VTK,sumedhasingla/VTK,demarle/VTK,SimVascular/VTK,candy7393/VTK,sumedhasingla/VTK,johnkit/vtk-dev,hendradarwin/VTK,berendkleinhaneveld/VTK,hendradarwin/VTK,gram526/VTK,gram526/VTK,sumedhasingla/VTK,hendradarwin/VTK,berendkleinhaneveld/VTK,sankhesh/VTK,gram526/VTK,berendkleinhaneveld/VTK,ashray/VTK-EVM,gram526/VTK,sumedhasingla/VTK,mspark93/VTK,keithroe/vtkoptix,demarle/VTK,SimVascular/VTK,sumedhasingla/VTK,candy7393/VTK,jmerkow/VTK,hendradarwin/VTK,johnkit/vtk-dev,johnkit/vtk-dev,gram526/VTK,SimVascular/VTK,demarle/VTK,gram526/VTK,candy7393/VTK,jmerkow/VTK,candy7393/VTK,johnkit/vtk-dev,ashray/VTK-EVM,SimVascular/VTK,jmerkow/VTK,keithroe/vtkoptix,mspark93/VTK,msmolens/VTK,mspark93/VTK,jmerkow/VTK,berendkleinhaneveld/VTK,msmolens/VTK,candy7393/VTK,sankhesh/VTK,sankhesh/VTK,keithroe/vtkoptix,demarle/VTK,jmerkow/VTK,jmerkow/VTK,sumedhasingla/VTK,ashray/VTK-EVM,candy7393/VTK,demarle/VTK,berendkleinhaneveld/VTK,ashray/VTK-EVM,gram526/VTK,ashray/VTK-EVM,SimVascular/VTK,candy7393/VTK,SimVascular/VTK,mspark93/VTK,msmolens/VTK,johnkit/vtk-dev,ashray/VTK-EVM,jmerkow/VTK,SimVascular/VTK,mspark93/VTK,msmolens/VTK,sankhesh/VTK,keithroe/vtkoptix,johnkit/vtk-dev,msmolens/VTK,demarle/VTK,keithroe/vtkoptix,gram526/VTK,berendkleinhaneveld/VTK,demarle/VTK,msmolens/VTK,hendradarwin/VTK,msmolens/VTK,mspark93/VTK,candy7393/VTK,sankhesh/VTK,keithroe/vtkoptix,sumedhasingla/VTK,mspark93/VTK,SimVascular/VTK,sankhesh/VTK,ashray/VTK-EVM,mspark93/VTK,demarle/VTK,berendkleinhaneveld/VTK,keithroe/vtkoptix,hendradarwin/VTK,johnkit/vtk-dev