PK_ERROR_code_t  PK_BODY_ask_first_edge
(
--- received arguments ---
PK_BODY_t        body,         --- a body

--- returned arguments ---
PK_EDGE_t *const first_edge     --- an edge (possibly PK_ENTITY_null)
)


This function returns an edge in the given body, if one exists, otherwise
PK_ENTITY_null.


This function should be used in conjunction with PK_EDGE_ask_next_in_body
to scan the edges in a body.