Some simple itkNotUsed(...) to fix warnings that came up on Mac.

Change-Id: I4b2a3a7d05c59b06e3ed2dbf1b5d224b02352ee4
Removed basically empty methods from itkTubeTubeNetworkExtractor.txx

Change-Id: I600bf0baa6c80ecf981c6fee9e98987ff0e475fb
Adjusted itkTubeTubeNetworkExtractor.h to reflect removal of methods.

Change-Id: Ief0d160300a12be18aa8f1da8df90659a8be364b
Merge topic 'rk-MacWarnings'

93fdbfb Adjusted itkTubeTubeNetworkExtractor.h to reflect removal of methods.
d1b2c82 Removed basically empty methods from itkTubeTubeNetworkExtractor.txx
9906d5e Some simple itkNotUsed(...) to fix warnings that came up on Mac.