unsupported/Eigen/src/NumericalDiff/InternalHeaderCheck.h - eigen - Git at Google

 #ifndef EIGEN_NUMERICALDIFF_MODULE_H
 #error "Please include unsupported/Eigen/NumericalDiff instead of including headers inside the src directory directly."
 #endif
	#ifndef EIGEN_NUMERICALDIFF_MODULE_H
	#error "Please include unsupported/Eigen/NumericalDiff instead of including headers inside the src directory directly."
	#endif