code: def transform_pip_requirement_set(self, requirement_set):
          
          filtered_requirements = []
          for requirement in requirement_set.requirements.values():
              # The `satisfied_by' property is set by pip when a requirement is
              # already satisfied (i.e. a version of the package that satisfies
              # the requirement is already installed) and -I, --ignore-installed
              # is not used. We filter out these requirements because pip never
              # unpacks distributions for these requirements, so pip-accel can't
              # do anything useful with such requirements.
              if requirement.satisfied_by:
                  continue
              # The `constraint' property marks requirement objects that
              # constrain the acceptable version(s) of another requirement but
              # don't define a requirement themselves, so we filter them out.
              if requirement.constraint:
                  continue
              # All other requirements are reported to callers.
              filtered_requirements.append(requirement)
              self.reported_requirements.append(requirement)
          return sorted([Requirement(self.config, r) for r in filtered_requirements],
                        key=lambda r: r.name.lower())
docs: Transform pip's requirement set into one that `pip-accel` can work with.
  
          :param requirement_set: The :class:`pip.req.RequirementSet` object
                                  reported by pip.
          :returns: A list of :class:`pip_accel.req.Requirement` objects.
  
          This function converts the :class:`pip.req.RequirementSet` object
          reported by pip into a list of :class:`pip_accel.req.Requirement`
          objects.