def arguments
      case self.type
      when :def, :block
        ArgumentsNode.new self.children[1]
      when :defs
        ArgumentsNode.new self.children[2]
      when :send
        self.children[2..-1]
      when :defined?
        self.children
      else
        raise Synvert::Core::MethodNotSupported.new "arguments is not handled for #{self.debug_info}"
      end
    end
def arguments
      case self.type
      when :def, :block
        ArgumentsNode.new self.children[1]
      when :defs
        ArgumentsNode.new self.children[2]
      when :send
        self.children[2..-1]
      when :defined?
        self.children
      else
        raise Synvert::Core::MethodNotSupported.new "arguments is not handled for #{self.debug_info}"
      end
    end
Get arguments node of :send, :block or :defined? node.

 @return [Array<Parser::AST::Node>] arguments node.
 @raise [Synvert::Core::MethodNotSupported] if calls on other node.