old_contents: class pytorch(PythonWig):
  	git_uri = 'https://github.com/pytorch/pytorch'
  	dependencies = ['numpy', 'cmake'] #, 'pip-pyyaml', 'pip-cffi', 'setuptools']
  	optional_dependencies = ['magma']
  	supported_features = ['cuda']
  	default_features = ['cuda']
  
  	def switch_cuda(self, on):
  		if on:
  			self.require('magma')
  		else:
  			self.before_install += [S.export('NO_CUDA', '1')]
  
new_contents: class pytorch(PythonWig):
  	git_uri = 'https://github.com/pytorch/pytorch'
  	dependencies = ['numpy', 'cmake'] #, 'pip-pyyaml', 'pip-cffi', 'setuptools']
  	optional_dependencies = ['magma']
  	supported_features = ['cuda']
  	default_features = ['+cuda']
  
  	def switch_cuda(self, on):
  		if on:
  			self.require('magma')
  		else:
  			self.before_install += [S.export('NO_CUDA', '1')]
  
subject: Update pytorch.py