code: def _get_qualifier_repo(self, namespace):
          
          self._validate_namespace(namespace)
          if namespace not in self.qualifiers:
              self.qualifiers[namespace] = NocaseDict()
          return self.qualifiers[namespace]
docs: Returns the qualifier repository for the specified CIM namespace
          within the mock repository. This is the original instance variable,
          so any modifications will change the mock repository.
  
          Validates that the namespace exists in the mock repository.
  
          If the qualifier repository does not contain the namespace yet, it is
          added.
  
          Parameters:
  
            namespace(:term:`string`): Namespace name. Must not be `None`.
  
          Returns:
  
            dict of CIMQualifierDeclaration: Qualifier repository.
  
          Raises:
  
            :exc:`~pywbem.CIMError`: CIM_ERR_INVALID_NAMESPACE: Namespace does
              not exist.