code: public int pushSegment(Segment seg) {
  		assert (m_input_segments.size() < 2);
  		m_input_segments.add(newIntersectionPart_(seg));
  		// m_param_1.resize(15);
  		// m_param_2.resize(15);
  		return (int) m_input_segments.size() - 1;
  	}
docs: Two segments has to be pushed for the intersect method to succeed.