SHELL_SCRIPT
  COMMANDS_LIST
    GENERIC_COMMAND_DIRECTIVE
      LITERAL
        PsiElement(word)('a')
  PsiElement(\n)('\n')
  COMMANDS_LIST
    SIMPLE_COMMAND
      GENERIC_COMMAND_DIRECTIVE
        LITERAL
          PsiElement(word)('a')
      PsiWhiteSpace(' ')
      LITERAL
        PsiElement(word)('b')
    PsiWhiteSpace(' ')
    PsiElement(&)('&')