--- /dev/null
+#ifndef _FLOWUTIL_H
+#define _FLOWUTIL_H 1
+
+#include <vector>
+#include "flowpusher.h"
+
+std::vector<flow_element> sum_flows(const std::vector<flow_element> &a, const std::vector<flow_element> &b);
+std::vector<flow_element> filter_flow(const std::vector<flow_element> &flow);
+void make_graph(int port, unsigned width, unsigned height, unsigned min_x, unsigned max_x, unsigned long long min_y, unsigned long long max_y, std::vector<flow_element> &flow);
+
+#endif /* !defined(_FLOWUTIL_H) */