def _reconcile_index_and_tool(lst_of_conc, given_idx, tool):
"""Given a list of Concrete objects with metadata (e.g., `DependencyParse`s)
and a default index, find the index of the object whose `.metadata.tool`
matches the provided query tool name `tool`.
When no tool is provided (but with an iterable list), this returns the
provided default index (even if it\'s not a valid index).
If the tool isn't found, the list is None or empty, this returns -1.
"""
valid_lst = lst_of_conc is not None and len(lst_of_conc) > 0
idx = given_idx if valid_lst else -1
if tool is not None:
idx = get_index_of_tool(lst_of_conc, tool)
return idx