@NotNull
  private static PyRequirement createVcsOrArchiveRequirement(@NotNull Pair<String, String> nameAndVersion,
                                                             @NotNull List<String> installOptions,
                                                             @Nullable String extras) {
    final String name = nameAndVersion.getFirst();
    final String version = nameAndVersion.getSecond();

    if (version == null) {
      if (extras == null) {
        return new PyRequirementImpl(name, Collections.emptyList(), installOptions, "");
      }
      else {
        return new PyRequirementImpl(name, Collections.emptyList(), installOptions, extras);
      }
    }

    final List<PyRequirementVersionSpec> versionSpecs = Collections.singletonList(PyRequirementsKt.pyRequirementVersionSpec(
      PyRequirementRelation.EQ, version));
    if (extras == null) {
      return new PyRequirementImpl(name, versionSpecs, installOptions, "");
    }
    else {
      return new PyRequirementImpl(name, versionSpecs, installOptions, extras);
    }
  }
@NotNull
  private static PyRequirement createVcsOrArchiveRequirement(@NotNull Pair<String, String> nameAndVersion,
                                                             @NotNull List<String> installOptions,
                                                             @Nullable String extras)