def get_multifile_object_child_location(self, parent_item_prefix: str, child_name: str) -> str:
check_var(parent_item_prefix, var_types=str, var_name='<STR_LIT>')<EOL>check_var(child_name, var_types=str, var_name='<STR_LIT>')<EOL>if not isdir(parent_item_prefix):<EOL><INDENT>raise ValueError(<EOL>'<STR_LIT>' + parent_item_prefix)<EOL><DEDENT>return join(parent_item_prefix, child_name)<EOL>
Implementation of the parent abstract method.
In this mode the attribute is a file inside the parent object folder

:param parent_item_prefix: the absolute file prefix of the parent item.
:return: the file prefix for this attribute