-const char *ident_get_host (graph_ident_t *ident);
-const char *ident_get_plugin (graph_ident_t *ident);
-const char *ident_get_plugin_instance (graph_ident_t *ident);
-const char *ident_get_type (graph_ident_t *ident);
-const char *ident_get_type_instance (graph_ident_t *ident);
-const char *ident_get_field (graph_ident_t *ident,
+const char *ident_get_host (const graph_ident_t *ident);
+const char *ident_get_plugin (const graph_ident_t *ident);
+const char *ident_get_plugin_instance (const graph_ident_t *ident);
+const char *ident_get_type (const graph_ident_t *ident);
+const char *ident_get_type_instance (const graph_ident_t *ident);
+const char *ident_get_field (const graph_ident_t *ident,