<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def prepare_zoho_headers(token, headers=None):
 """Add a `Zoho Token`_ to the request URI. Recommended method of passing bearer tokens. Authorization: Zoho-oauthtoken h480djs93hd8 .. _`Zoho-oauthtoken Token`: custom zoho token """

        headers = headers or {}
        headers["Authorization"] = "{token_header} {token}".format(
            token_header=ZOHO_TOKEN_HEADER, token=token
        )
        return headers