parameters: (ws, ws_out, x_start, x_end)
docstring: Extracts a part of the workspace and
      shifts the x-axis to start from 0
      @param  ws      :: input workspace name
      @param  ws_out  :: output workspace name
      @param  x_start :: start bin of workspace to be extracted
      @param  x_end   :: end bin of workspace to be extracted
docstring_summary: Extracts a part of the workspace and
      shifts the x-axis to start from 0
docstring_tokens: Extracts a part of the workspace and shifts the x - axis to start from 0
function: def _extract_workspace(ws, ws_out, x_start, x_end):
      """
      Extracts a part of the workspace and
      shifts the x-axis to start from 0
      @param  ws      :: input workspace name
      @param  ws_out  :: output workspace name
      @param  x_start :: start bin of workspace to be extracted
      @param  x_end   :: end bin of workspace to be extracted
      """
      CropWorkspace(InputWorkspace=ws, OutputWorkspace=ws_out, XMin=x_start, XMax=x_end)
      ScaleX(InputWorkspace=ws_out, OutputWorkspace=ws_out, Factor=-x_start, Operation='Add')
function_tokens: def _extract_workspace ( ws , ws_out , x_start , x_end ) : CropWorkspace ( InputWorkspace = ws , OutputWorkspace = ws_out , XMin = x_start , XMax = x_end ) ScaleX ( InputWorkspace = ws_out , OutputWorkspace = ws_out , Factor = - x_start , Operation = 'Add' )