<AnchorPane focusTraversable="true" prefHeight="700.0" prefWidth="1034.0" style="-fx-padding: 0;" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.linkedin.people.parser.controller.AppController">
   <children>
      <GridPane alignment="CENTER" gridLinesVisible="true" prefHeight="700.0" prefWidth="1034.0">
        <columnConstraints>
          <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
        </columnConstraints>
        <rowConstraints>
          <RowConstraints maxHeight="50.0" minHeight="50.0" prefHeight="50.0" vgrow="SOMETIMES" />
          <RowConstraints maxHeight="684.0" minHeight="10.0" prefHeight="662.0" vgrow="SOMETIMES" />
        </rowConstraints>
         <children>
            <Pane prefHeight="200.0" prefWidth="200.0">
               <children>
                  <Label layoutY="10.0" prefHeight="30.0" prefWidth="185.0" text="App name">
                     <padding>
                        <Insets left="10.0" />
                     </padding>
                     <font>
                        <Font name="System Bold" size="15.0" />
                     </font>
                  </Label>
                  <Button fx:id="newSession" layoutX="916.0" layoutY="9.0" mnemonicParsing="false" text="New Session" />
               </children>
            </Pane>
            <TabPane fx:id="sessions" tabClosingPolicy="UNAVAILABLE" GridPane.halignment="CENTER" GridPane.hgrow="ALWAYS" GridPane.rowIndex="1">
               <tabs>
                  <Tab text="Untitled Tab">
                    <content>
                      <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="200.0" />
                    </content>
                  </Tab>
               </tabs></TabPane>
         </children>
      </GridPane>
   </children>
</AnchorPane>

@Override
public void start(Stage primaryStage) throws Exception {

    this.stage = primaryStage;

    FXMLLoader loader = new FXMLLoader();

    loader.load(Main.class.getClassLoader().getResourceAsStream("app.fxml"));

    this.stage.setResizable(false);
    this.stage.setTitle("Title");
    this.stage.setScene(new Scene(loader.getRoot()));

    AppController controller = loader.getController();
    controller.setMain(this);
    this.stage.show();

}