@Nullable
  @Override
  public Collection<ConstraintFormula> reduceTypeConstraint(@NotNull PsiType leftType,
                                                            @NotNull PsiType rightType,
                                                            @NotNull Position position,
                                                            @NotNull PsiElement context) {
    if (position == Position.METHOD_PARAMETER &&
        isClassType(leftType, JAVA_LANG_STRING) &&
        isClassType(rightType, GROOVY_LANG_GSTRING)) {
      return Collections.emptyList();
    }
    else {
      return null;
    }
  }
@Nullable
  @Override
  public Collection<ConstraintFormula> reduceTypeConstraint(@NotNull PsiType leftType,
                                                            @NotNull PsiType rightType,
                                                            @NotNull Position position,
                                                            @NotNull PsiElement context)