Avoid importing twice in autogen

Author: vidartf

js/scripts/generate-wrappers.js

@@ -131,6 +131,16 @@ Handlebars.registerHelper('rst', function (data, indent) {
     return new Handlebars.SafeString(out);
 });
 
+Handlebars.registerHelper('notSuper', function (v1, options) {
+    if (v1 === (
+        options.data.root.superClass.modelName ||
+        options.data.root.superClass.className
+    )) {
+        return options.inverse(this);
+    }
+    return options.fn(this);
+});
+
 //
 // Helper Functions
 //

js/scripts/templates/js_wrapper.mustache

@@ -3,6 +3,7 @@
 //
 
 var _ = require('underscore');
+var Promise = require('bluebird');
 var THREE = require('three');
 var widgets = require('@jupyter-widgets/base');
 var dataserializers = require('jupyter-dataserializers');
@@ -11,7 +12,9 @@ var serializers = require('{{ relativePathToBase }}/_base/serializers');
 var {{ superClass.modelName }} = require('{{ superClass.requirePath }}').{{ superClass.modelName }};
 
 {{#each dependencies as |dep depName|}}
+{{#notSuper dep.modelName}}
 var {{ dep.modelName }} = require('{{ dep.requirePath }}').{{ dep.modelName }};
+{{/notSuper}}
 {{/each}}
 
 var {{ modelName }} = {{ superClass.modelName }}.extend({

js/scripts/templates/py_wrapper.mustache

@@ -16,7 +16,9 @@ from {{ py_base_relative_path }}traits import *
 from {{ superClass.pyRelativePath }} import {{ superClass.className }}
 
 {{#each dependencies as |dep depName|}}
+{{#notSuper dep.className}}
 from {{ dep.pyRelativePath }} import {{ dep.className }}
+{{/notSuper}}
 {{/each}}
 
 {{#unless hasOverride}}