Groovy script
  Call expression
    Reference expression
      PsiElement(identifier)('foo')
    PsiWhiteSpace(' ')
    Command arguments
      Literal
        PsiElement(string)(''a'')
      PsiElement(,)(',')
      PsiWhiteSpace(' ')
      Closable block
        PsiElement({)('{')
        Parameter list
          <empty list>
        PsiElement(})('}')
---
Groovy script
  Call expression
    Reference expression
      PsiElement(identifier)('foo')
    PsiWhiteSpace(' ')
    Command arguments
      Literal
        PsiElement(string)(''a'')
      PsiElement(,)(',')
      PsiWhiteSpace(' ')
      Closable block
        PsiElement({)('{')
        PsiWhiteSpace('\n    \n')
        Parameter list
          <empty list>
        PsiElement(})('}')