Stimulus: support for R internal functions

Two HSBM functions are internal

interfaces/functions.def

@@ -327,6 +327,7 @@ igraph_hsbm_game:
         GATTR-R: name IS Hierarchical stochastic block model
         GATTR-PARAM-R: m, rho, C, p
         IGNORE: RNamespace
+        INTERNAL: True
 
 igraph_hsbm_list_game:
         PARAMS: OUT GRAPH graph, INTEGER n, VECTOR_INT mlist, \
@@ -335,6 +336,7 @@ igraph_hsbm_list_game:
         GATTR-R: name IS Hierarchical stochastic block model
         GATTR-PARAM-R: p
         IGNORE: RNamespace
+        INTERNAL: True
 
 igraph_correlated_game:
         PARAMS: GRAPH old_graph, OUT GRAPH new_graph, \

tools/stimulus.py

@@ -353,7 +353,10 @@ def generate_function(self, function, out):
             params[p].setdefault('mode', 'IN')
 
         ## Roxygen to export the function
-        out.write("#' @export\n")
+        internal = self.func[function].get("INTERNAL")
+        print internal
+        if internal is None or internal == 'False':
+            out.write("#' @export\n")
 
         ## Header
         ## do_par handles the translation of a single argument in the