parameters: (self, *requirements)
return_statement: return needed
docstring: Ensure that distributions matching `requirements` are activated
  
          `requirements` must be a string or a (possibly-nested) sequence
          thereof, specifying the distributions and versions required.  The
          return value is a sequence of the distributions that needed to be
          activated to fulfill the requirements; all relevant distributions are
          included, even if they were already activated in this working set.
docstring_summary: Ensure that distributions matching `requirements` are activated
docstring_tokens: Ensure that distributions matching requirements are activated
function: def require(self, *requirements):
          """Ensure that distributions matching `requirements` are activated
  
          `requirements` must be a string or a (possibly-nested) sequence
          thereof, specifying the distributions and versions required.  The
          return value is a sequence of the distributions that needed to be
          activated to fulfill the requirements; all relevant distributions are
          included, even if they were already activated in this working set.
          """
          needed = self.resolve(parse_requirements(requirements))
  
          for dist in needed:
              self.add(dist)
  
          return needed
function_tokens: def require ( self , * requirements ) : needed = self . resolve ( parse_requirements ( requirements ) ) for dist in needed : self . add ( dist ) return needed