code: def merged_with(self, provider, requirement, parent):
          
          infos = list(self.information)
          infos.append(RequirementInformation(requirement, parent))
          candidates = [
              c for c in self.candidates
              if provider.is_satisfied_by(requirement, c)
          ]
          if not candidates:
              raise RequirementsConflicted(self)
          return type(self)(candidates, infos)
docs: Build a new instance from this and a new requirement.