text: #ifndef __Hdf5_Field_Extraction_vol_m_h__
  #define __Hdf5_Field_Extraction_vol_m_h__
  
  #include "Hdf5FieldExtraction.h"
  
  class Hdf5FieldExtraction_vol_m : public Hdf5FieldExtraction
  {
  protected:
  	bool all_fld_is_found;
  	size_t m_s_offset, density_s_offset, n_offset;
  
  public:
  	Hdf5FieldExtraction_vol_m() : all_fld_is_found(false) {}
  	Hdf5FieldExtraction_vol_m(Hdf5DataLoader& loader) :
  		all_fld_is_found(false), Hdf5FieldExtraction(loader) {}
  	~Hdf5FieldExtraction_vol_m() {}
  
  	bool validate_data_type() override;
  	int extract_pcl_fld_data(double* pcl_fld_data) override;
  };
  
  #endif