interface a {}
-----
Groovy script
  Interface definition
    Modifiers
      <empty list>
    PsiElement(interface)('interface')
    PsiWhiteSpace(' ')
    PsiElement(identifier)('a')
    Extends clause
      <empty list>
    PsiWhiteSpace(' ')
    Type definition body
      PsiElement({)('{')
      PsiElement(})('}')