requires doc_attrs and a block

I was trying to write something along the lines of

params do 
  requires :request, type:Hash, desc: 'Request Wrapper required for all API requests', documentation:{example: 'request:{}'} do 
    requires :dealer_id, type:Integer,default: 0, desc: 'Dealer Id Number', documentation:{example: 100001}
  end
end

Which seemed like it should work appropriately as I need to document the wrapper as well as the parameters inside it but I was receiving an standard ArgumentError. So I started digging through the source and traced it all down to Grape::Validations::ParamsScope#new_scope

def new_scope(attrs, optional = false, &block)
  opts = attrs[1] || { type: Array }
  raise ArgumentError unless opts.keys.to_set.subset? [:type].to_set
  ParamsScope.new(api: @api, element: attrs.first, parent: self, optional: optional, type: opts[:type], &block)
end

My issue is why are we checking to make sure that my options are a subset? of a single element wouldn't equality work better here? Unless of course we are looking to see if [:type].to_set is a #subset? of my opts which seems more like the intended behavior in which case I am proposing changing #new_scope to

def new_scope(attrs, optional = false, &block)
  opts = attrs[1] || { type: Array }
  raise ArgumentError unless opts.keys.to_set.superset? [:type].to_set
  ParamsScope.new(api: @api, element: attrs.first, parent: self, optional: optional, type: opts[:type], &block)
end

This would then allow me to use #requires with doc_attrs and a block. Does this some how cause interference elsewhere that I am overlooking? Can someone explain to me why you would check to see if {type: Array}.keys.to_set is a subset of [:type].to_set when this truely evaluates to {type: Array}.keys.to_set == [:type].to_set? because a subset of a single item must be equal to that single item.

Start at Grape::Validations::ParamsScope#new_scope and reproduce the nested requires example from the issue. Inspect how its option-key check handles doc_attrs and blocks; the work is done when the example no longer raises ArgumentError and the behavior is covered by a regression test.