[ << label >> [ << label >> ] ...]
  { assignment_statement
  | basic_loop_statement
  | case_statement
  | close_statement
  | continue_statement
  | cursor_for_loop_statement
  | execute_immediate_statement
  | exit_statement
  | fetch_statement
  | for_loop_statement
  | forall_statement
  | goto_statement
  | if_statement
  | null_statement
  | open_statement
  | open_for_statement
  | pipe_row_statement
  | plsql_block
  | raise_statement
  | return_statement
  | select_into_statement
  | sql_statement
  | while_loop_statement
  }