parameters: (self, filename)
docstring: Ensure that `filename` appears in the data, empty if needed.
docstring_summary: Ensure that `filename` appears in the data, empty if needed.
docstring_tokens: Ensure that filename appears in the data empty if needed .
function: def touch_file(self, filename):
          """Ensure that `filename` appears in the data, empty if needed."""
          if self._debug and self._debug.should('dataop'):
              self._debug.write("Touching %r" % (filename,))
          if not self._has_arcs() and not self._has_lines():
              raise CoverageException("Can't touch files in an empty CoverageData")
  
          if self._has_arcs():
              where = self._arcs
          else:
              where = self._lines
          where.setdefault(filename, [])
  
          self._validate()
function_tokens: def touch_file ( self , filename ) : if self . _debug and self . _debug . should ( 'dataop' ) : self . _debug . write ( "Touching %r" % ( filename , ) ) if not self . _has_arcs ( ) and not self . _has_lines ( ) : raise CoverageException ( "Can't touch files in an empty CoverageData" ) if self . _has_arcs ( ) : where = self . _arcs else : where = self . _lines where . setdefault ( filename , [ ] ) self . _validate ( )