docs: def _sanity_check(self):
          """Check if parameters are okay.
  
          Sanity check makes sure each parameter is within an allowable range.
  
          Raises:
              ValueError: Problem with a specific parameter.
  
          """
          if any(self.m1 < 0.0):
              raise ValueError("Mass 1 is negative.")
          if any(self.m2 < 0.0):
              raise ValueError("Mass 2 is negative.")
  
          if any(self.z <= 0.0):
              raise ValueError("Redshift is zero or negative.")
  
          if any(self.dist <= 0.0):
              raise ValueError("Distance is zero or negative.")
  
          if any(self.initial_point < 0.0):
              raise ValueError("initial_point is negative.")
  
          if any(self.t_obs < 0.0):
              raise ValueError("t_obs is negative.")
  
          if any(self.e0 <= 0.0):
              raise ValueError("e0 must be greater than zero when using EccentricBinaries class.")
  
          if any(self.e0 > 1.0):
              raise ValueError("e0 greater than 1.")
  
          return