docs: def _pruneCMD(self, minimum_solid_angle):
          """
          Remove regions of color-magnitude space where the unmasked solid angle is
          statistically insufficient to estimate the background.
  
          ADW: Why are we clipping at the bin center instead of edge?
  
          INPUTS:
              solid_angle[1]: minimum solid angle (deg^2)
          """
  
          logger.info('Pruning mask based on minimum solid angle of %.2f deg^2'%(minimum_solid_angle))
          self.solid_angle_cmd *= self.solid_angle_cmd > minimum_solid_angle
  
          if self.solid_angle_cmd.sum() == 0:
              msg = "Pruned mask contains no solid angle."
              logger.error(msg)
              raise Exception(msg)
  
          # Compute which magnitudes the clipping correspond to
          index_mag, index_color = np.nonzero(self.solid_angle_cmd)
          mag = self.roi.centers_mag[index_mag]
          color = self.roi.centers_color[index_color]
          if self.config.params['catalog']['band_1_detection']:
              mag_1 = mag
              mag_2 = mag_1 - color
              self.mag_1_clip = np.max(mag_1) + (0.5 * self.roi.delta_mag)
              self.mag_2_clip = np.max(mag_2) + (0.5 * self.roi.delta_color)
          else:
              mag_2 = mag
              mag_1 = color + mag_2
              self.mag_1_clip = np.max(mag_1) + (0.5 * self.roi.delta_color)
              self.mag_2_clip = np.max(mag_2) + (0.5 * self.roi.delta_mag)
  
          logger.info('Clipping mask 1 at %.2f mag'%(self.mag_1_clip) )
          logger.info('Clipping mask 2 at %.2f mag'%(self.mag_2_clip) )
          self.mask_1.mask_roi_sparse = np.clip(self.mask_1.mask_roi_sparse, 0., self.mag_1_clip)
          self.mask_2.mask_roi_sparse = np.clip(self.mask_2.mask_roi_sparse, 0., self.mag_2_clip)