code: def check_covariance_Kgrad_x(covar, relchange=1E-5, threshold=1E-2, check_diag=True):
          
          return _core.ACovarianceFunction_check_covariance_Kgrad_x(covar, relchange, threshold, check_diag)
docs: check_covariance_Kgrad_x(ACovarianceFunction covar, limix::mfloat_t relchange=1E-5, limix::mfloat_t threshold=1E-2, bool check_diag=True) -> bool
  
          Parameters
          ----------
          covar: limix::ACovarianceFunction &
          relchange: limix::mfloat_t
          threshold: limix::mfloat_t
          check_diag: bool
  
          check_covariance_Kgrad_x(ACovarianceFunction covar, limix::mfloat_t relchange=1E-5, limix::mfloat_t threshold=1E-2) -> bool
  
          Parameters
          ----------
          covar: limix::ACovarianceFunction &
          relchange: limix::mfloat_t
          threshold: limix::mfloat_t
  
          check_covariance_Kgrad_x(ACovarianceFunction covar, limix::mfloat_t relchange=1E-5) -> bool
  
          Parameters
          ----------
          covar: limix::ACovarianceFunction &
          relchange: limix::mfloat_t
  
          check_covariance_Kgrad_x(ACovarianceFunction covar) -> bool
  
          Parameters
          ----------
          covar: limix::ACovarianceFunction &