# File lib/new_relic/agent/sql_sampler.rb, line 170
      def merge!(sql_traces)
        @samples_lock.synchronize do
          sql_traces.each do |trace|
            existing_trace = @sql_traces[trace.sql]
            if existing_trace
              existing_trace.aggregate_trace(trace)
            else
              @sql_traces[trace.sql] = trace
            end
          end
        end
      end