code: def svar_ckerr(svar_type, A, B):
      if A is None and (svar_type == "A" or svar_type == "AB"):
          raise ValueError(
              "SVAR of type A or AB but A array not given."
          )
      if B is None and (svar_type == "B" or svar_type == "AB"):
          raise ValueError(
              "SVAR of type B or AB but B array not given."
          )
  
imports: import numpy
  import numpy.linalg
  from numpy.linalg import slogdet
  from statsmodels.tools.decorators import deprecated_alias
  from statsmodels.tools.numdiff import approx_fprime, approx_hess
  import statsmodels.tsa.base.tsa_model
  from statsmodels.tsa.vector_ar.irf import IRAnalysis
  import statsmodels.tsa.vector_ar.util
  from statsmodels.tsa.vector_ar.var_model import VARProcess, VARResults
label_desc: Use image node_id 1 for calling a global function with example usage: svar_ckerr(svar_type, A, B) without return types