# File lib/moped/query.rb, line 127
    def first
      reply = read_preference.with_node(cluster) do |node|
        node.query(
          operation.database,
          operation.collection,
          operation.selector,
          query_options(
            fields: operation.fields,
            flags: operation.flags,
            skip: operation.skip,
            limit: -1
          )
        )
      end
      reply.documents.first
    end