class Roda::RodaPlugins::TypecastParams::Params

no value for +key+, nil is returned instead of an array.
then this returns an array of arrays, one for each respective value of +key+. If there is
given, any +nil+ values in the array are replaced with +default+. If +key+ is an array
Convert the value of +key+ to an array of values of the given +type+. If +default+ is

def array(type, key, default=nil)
  meth = :"_convert_array_#{type}"
  raise ProgrammerError, "no typecast_params type registered for #{type.inspect}" unless respond_to?(meth, true)
  process_arg(meth, key, default, send(:"_max_input_bytesize_for_#{type}")) if require_hash!
end