code: def import_private_key(self, private_key):
          
          self.make_request(
              CertificateImportError,
              method='create',
              resource='private_key_import',
              headers = {'content-type': 'multipart/form-data'}, 
              files={ 
                  'private_key': open(private_key, 'rb') if not \
                      pem_as_string(private_key) else private_key
              })
docs: Import a private key. The private key can be a path to a file
          or the key in string format. If in string format, the key must
          start with -----BEGIN. Key types supported are PRIVATE RSA KEY
          and PRIVATE KEY.
          
          :param str private_key: fully qualified path to private key file
          :raises CertificateImportError: failure to import cert with reason
          :raises IOError: file not found, permissions, etc.
          :return: None