Update comments

vitessce/widget.py

@@ -393,14 +393,23 @@ def get_uid_str(uid):
 export default { createPlugins };
 """
 
-# Abstract class for widget plugins to subclass
-
 
 class VitesscePlugin:
+    """
+    A class that represents a Vitessce widget plugin. Custom plugins can be created by subclassing this class.
+    """
     plugin_esm = DEFAULT_PLUGIN_ESM
     commands = {}
 
     def on_config_change(self, new_config):
+        """
+        Config change handler.
+
+        :param dict new_config: The new config object.
+
+        :returns: config (likely with new "uid" property) or None
+        :rtype: dict or None
+        """
         raise NotImplementedError("on_config_change may optionally be implemented by subclasses.")
 
 
@@ -444,7 +453,7 @@ def __init__(self, config, height=600, theme='auto', uid=None, port=None, proxy=
         :param str js_package_version: The version of the NPM package ('vitessce' if not js_dev_mode else '@vitessce/dev').
         :param bool js_dev_mode: Should @vitessce/dev be used (typically for debugging purposes)? By default, False.
         :param str custom_js_url: A URL to a JavaScript file to use (instead of 'vitessce' or '@vitessce/dev' NPM package).
-        :param list[WidgetPlugin] plugins: A list of subclasses of WidgetPlugin, defining plugin_esm (string) and/or on_config_change (function). Optional.
+        :param list[WidgetPlugin] plugins: A list of subclasses of VitesscePlugin. Optional.
         :param bool remount_on_uid_change: Passed to the remountOnUidChange prop of the <Vitessce/> React component. By default, True.
 
         .. code-block:: python

vitessce/widget_plugins/spatial_query.py

@@ -138,7 +138,7 @@ def __init__(self, adata, spatial_key="X_spatial", label_key="cell_type"):
 
             plugin = SpatialQueryPlugin(adata, spatial_key="X_spatial", label_key="cell_type")
             # ...
-            vc.widget(plugins=[plugin])
+            vc.widget(plugins=[plugin], remount_on_uid_change=False)
         """
         from SpatialQuery.spatial_query import spatial_query
         import matplotlib.pyplot as plt  # Add as dependency / optional dependency?