String (z,a,x)
-----
Groovy script
  Method call
    Reference expression
      PsiElement(identifier)('String')
    PsiWhiteSpace(' ')
    Arguments
      PsiElement(()('(')
      Reference expression
        PsiElement(identifier)('z')
      PsiElement(,)(',')
      Reference expression
        PsiElement(identifier)('a')
      PsiElement(,)(',')
      Reference expression
        PsiElement(identifier)('x')
      PsiElement())(')')