class RuboCop::AST::DstrNode

its methods available to all ‘dstr` nodes within RuboCop.
in place of a plain node when the builder constructs the AST, making
A node extension for `dstr` nodes. This will be used

def value 

def value
  child_nodes.map do |child|
    child.respond_to?(:value) ? child.value : child.source
  end.join
end