Need help locating 'ekf_localization node' inside 'robot_localization' package

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I naviagted to the husky_control package using roscd husky_control. There exists a launch file inside the husky_control package named control.launch.

This is how the control.launch file looks.

<?xml version="1.0"?>
<launch>

  <arg name="multimaster" default="$(optenv ROBOT_MULTIMASTER false)"/>
  <arg name="simulation" default="$(optenv ROBOT_SIMULATION false)"/>
  <arg name="robot_namespace" default="$(optenv ROBOT_NAMESPACE robot)"/>
  <arg name="enable_ekf" default="$(optenv ENABLE_EKF true)"/>

  <arg name="config_extras"
       default="$(eval optenv('HUSKY_CONFIG_EXTRAS', find('husky_control') + '/config/empty.yaml'))"/>

  <arg name="laser_enabled" default="$(optenv HUSKY_LMS1XX_ENABLED false)"/>
  <arg name="realsense_enabled" default="$(optenv HUSKY_REALSENSE_ENABLED false)"/>
  <arg name="urdf_extras" default="$(optenv HUSKY_URDF_EXTRAS)"/>

  <include file="$(find multimaster_launch)/launch/multimaster_robot.launch" if="$(arg multimaster)">
    <arg name="gazebo_interface" value="$(find husky_control)/config/gazebo_interface.yaml" />
    <arg name="public_interface" value="$(find husky_control)/config/public_interface.yaml" />
    <arg name="robot_namespace" value="$(arg robot_namespace)"/>
    <arg name="simulation" value="$(arg simulation)"/>
  </include>

  <!-- Load robot description -->
  <include file="$(find husky_description)/launch/description.launch" >
    <arg name="laser_enabled" default="$(arg laser_enabled)"/>
    <arg name="realsense_enabled" default="$(arg realsense_enabled)"/>
    <arg name="urdf_extras" default="$(arg urdf_extras)"/>
  </include>

  <!-- Load controller configuration -->
  <rosparam command="load" file="$(find husky_control)/config/control.yaml" />

  <!-- Spawn controllers -->
  <node name="base_controller_spawner" pkg="controller_manager" type="spawner"
        args="husky_joint_publisher husky_velocity_controller"/>

  <!-- Start EKF for localization -->
  <group if="$(arg enable_ekf)" >
    <node pkg="robot_localization" type="ekf_localization_node" name="ekf_localization">
      <rosparam command="load" file="$(find husky_control)/config/localization.yaml" />
    </node>
  </group>

  <node pkg="interactive_marker_twist_server" type="marker_server" name="twist_marker_server" output="screen"/>

  <node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher" />

  <node pkg="twist_mux" type="twist_mux" name="twist_mux">
    <rosparam command="load" file="$(find husky_control)/config/twist_mux.yaml" />
    <remap from="cmd_vel_out" to="husky_velocity_controller/cmd_vel"/>
  </node>

  <!-- Override the default control parameters, see config/empty.yaml for default. -->
  <rosparam command="load" file="$(arg config_extras)" />

</launch>

As we can see, there's an ekf_localization_node inside the robot_localization package. But, when I run the command roscd robot_localization, and navigate to the robot_localization package in my system, I only see the following files/folders:

  - cmake (folder)
  - launch (folder)
  - LICENSE
  - nodelet_plugins.xml
  - package.xml
  - params (folder)
  - srv (folder)

Why don't I see the ekf_localization_node inside the robot_localization package? What am I missing?