Need to ensure that the server is alive when using scenegraph. Otherwise, a request attempt might happen while the server is still loading and therefore fail. See discussion at stanfordnlp/CoreNLP#1346

Author: AngledLuffa

stanza/server/client.py

@@ -699,6 +699,11 @@ def scenegraph(self, text, properties=None):
 
         This will require a new CoreNLP release, 4.5.5 or later
         """
+        # since we're using requests ourself,
+        # check if the server has started or not
+        if self.start_server is not StartServer.DONT_START:
+            self.ensure_alive()
+
         if properties is None:
             properties = {}
         # the only thing the scenegraph knows how to use is text