def merged_chain_dsl(&block)
      Chain::DSL.build(registry.merge(DSL.registry(&block)))
    end
def merged_chain_dsl(&block)
      Chain::DSL.build(registry.merge(DSL.registry(&block)))
    end
Return a new {Chain::DSL} by merging in +other.registry+

 @param [Environment] other
   the other environment providing the registry to merge

 @return [Chain::DSL]

 @api private