code: def _check_integrity(self, lons, lats):
          
  
          lons = np.array(lons).ravel()
          lats = np.array(lats).ravel()
  
          if len(lons.shape) != 1 or len(lats.shape) != 1:
              raise ValueError('lons and lats must be 1D')
          if lats.size != lons.size:
              raise ValueError('lons and lats must have same length')
          if (np.abs(lons)).max() > 2.*np.pi:
              raise ValueError("lons must be in radians (-2*pi <= lon <= 2*pi)")
          if (np.abs(lats)).max() > 0.5*np.pi:
              raise ValueError("lats must be in radians (-pi/2 <= lat <= pi/2)")
          return lons, lats
docs: Ensure lons and lats are:
           - 1D numpy arrays
           - equal size
           - within the appropriate range in radians