private static PsiType getIntroducedVariableType(PsiExpression expression) {
      final PsiType type = expression.getType();
      if (type instanceof PsiClassType) {
        final PsiType[] parameters = ((PsiClassType)type).getParameters();
        if (parameters.length == 1) {
          final PsiType parameter = parameters[0];
          if (parameter instanceof PsiClassType) {
            return parameter;
          }
        }
      }
      return null;
    }
private static PsiType getIntroducedVariableType(PsiExpression expression)