def register(converter = nil, &block)
      converter ||= Converter.create(&block)
      key = generate_key(converter)
      converter = add_config(converter, @configuration)
      return false if converter_map.key?(key)
      converter_map[key] = converter
      true
    end
def register(converter = nil, &block)
      converter ||= Converter.create(&block)
      key = generate_key(converter)
      converter = add_config(converter, @configuration)
      return false if converter_map.key?(key)
      converter_map[key] = converter
      true
    end
Register a converter

 @example with simple object
   conversions.register NullConverter.new(:array, :array)

 @example with block
   conversions.register do |c|
     c.source = :array
     c.target = :array
     c.convert = -> { |val, options| val }
   end

 @api public