Example code for YAMLTree is broken for Ruby 2.5+

[movermeyer]

What is the problem?

On this page, It shows the following example code:

builder = Psych::Visitors::YAMLTree.new
builder << { :foo => 'bar' }
builder.tree # => #<Psych::Nodes::Stream .. }

This seems to work up until 2.4.0. In 2.5.0+, it seems that the optional parameters for new became mandatory:

pry(main)> builder = Psych::Visitors::YAMLTree.new
ArgumentError: wrong number of arguments (given 0, expected 3)

What was the expected behaviour?

I expected that the sample code on a docs page should be valid for the particular version of Ruby I'm looking at.

If you have an idea for a potential fix, list it here

IDK