docs: public void setObservations( List<Point2D_F64> observations , List<Se3_F64> motionGtoC ) {
  		if( observations.size() != motionGtoC.size() )
  			throw new IllegalArgumentException("Different size lists");
  
  		this.observations = observations;
  		this.motionGtoC = motionGtoC;
  	}