WP_Customize_Manager::add_section PHP Method

    public function add_section($id, $args = array())
    {
        if ($id instanceof WP_Customize_Section) {
            $section = $id;
        } else {
            $section = new WP_Customize_Section($this, $id, $args);
        }
        $this->sections[$section->id] = $section;
        return $section;
    }

/**
 * Implement Theme Customizer additions and adjustments.
 * Static front page priority is 120, so we assign our section priorities higher
 *
 * @param WP_Customize_Manager $wp_customize Theme Customizer object.
 */
function bigblank_customize_register($wp_customize)
{
    // Add postMessage support for site title and description.
    $wp_customize->get_setting('blogname')->transport = 'postMessage';
    $wp_customize->get_setting('blogdescription')->transport = 'postMessage';
    // Rename the label to "Display Site Title & Tagline" in order to make this option extra clear.
    $wp_customize->get_control('display_header_text')->label = __('Display Site Title & Tagline', 'bigblank');
    $wp_customize->get_setting('blogname')->transport = 'postMessage';
    $wp_customize->get_setting('blogdescription')->transport = 'postMessage';
    $defaults = bigblank_get_default_theme_options();
    // Contact Section
    $wp_customize->add_section('contact', array('title' => __('Contact Settings', 'bigblank'), 'priority' => 140));
    // phone text
    $wp_customize->add_setting('bigblank_theme_options[phone]', array('type' => 'option', 'default' => $defaults['phone']));
    $wp_customize->add_control('bigblank_theme_options[phone]', array('label' => __('Phone Number', 'bigblank'), 'section' => 'contact', 'settings' => 'bigblank_theme_options[phone]'));
    // address text
    $wp_customize->add_setting('bigblank_theme_options[address]', array('type' => 'option', 'default' => $defaults['address']));
    $wp_customize->add_control('bigblank_theme_options[address]', array('label' => __('Address', 'bigblank'), 'section' => 'contact', 'settings' => 'bigblank_theme_options[address]'));
    // social section
    $wp_customize->add_section('social', array('title' => __('Social Links', 'bigblank'), 'priority' => 150));
    // twitter
    $wp_customize->add_setting('bigblank_theme_options[twitter]', array('type' => 'option', 'default' => $defaults['twitter']));
    $wp_customize->add_control('bigblank_theme_options[twitter]', array('label' => __('Twitter', 'bigblank'), 'section' => 'social', 'settings' => 'bigblank_theme_options[twitter]'));
    // facebook
    $wp_customize->add_setting('bigblank_theme_options[facebook]', array('type' => 'option', 'default' => $defaults['facebook']));
    $wp_customize->add_control('bigblank_theme_options[facebook]', array('label' => __('Facebook', 'bigblank'), 'section' => 'social', 'settings' => 'bigblank_theme_options[facebook]'));
    // google+
    $wp_customize->add_setting('bigblank_theme_options[googleplus]', array('type' => 'option', 'default' => $defaults['googleplus']));
    $wp_customize->add_control('bigblank_theme_options[googleplus]', array('label' => __('Google+', 'bigblank'), 'section' => 'social', 'settings' => 'bigblank_theme_options[googleplus]'));
    // instagram
    $wp_customize->add_setting('bigblank_theme_options[instagram]', array('type' => 'option', 'default' => $defaults['instagram']));
    $wp_customize->add_control('bigblank_theme_options[instagram]', array('label' => __('Instagram', 'bigblank'), 'section' => 'social', 'settings' => 'bigblank_theme_options[instagram]'));
    // youtube
    $wp_customize->add_setting('bigblank_theme_options[youtube]', array('type' => 'option', 'default' => $defaults['youtube']));
    $wp_customize->add_control('bigblank_theme_options[youtube]', array('label' => __('Youtube', 'bigblank'), 'section' => 'social', 'settings' => 'bigblank_theme_options[youtube]'));
    // pinterest
    $wp_customize->add_setting('bigblank_theme_options[pinterest]', array('type' => 'option', 'default' => $defaults['pinterest']));
    $wp_customize->add_control('bigblank_theme_options[pinterest]', array('label' => __('Pinterest', 'bigblank'), 'section' => 'social', 'settings' => 'bigblank_theme_options[pinterest]'));
    // Default Layout
    $wp_customize->add_section('bigblank_layout', array('title' => __('Layout', 'bigblank'), 'priority' => 130));
    $wp_customize->add_setting('bigblank_theme_options[theme_layout]', array('type' => 'option', 'default' => $defaults['theme_layout'], 'sanitize_callback' => 'sanitize_key'));
    $layouts = bigblank_layouts();
    $choices = array();
    foreach ($layouts as $layout) {
        $choices[$layout['value']] = $layout['label'];
    }
    $wp_customize->add_control('bigblank_theme_options[theme_layout]', array('section' => 'bigblank_layout', 'type' => 'radio', 'choices' => $choices));
    // Footer Section
    $wp_customize->add_section('footer', array('title' => __('Footer Settings', 'bigblank'), 'priority' => 160));
    // copyright text
    $wp_customize->add_setting('bigblank_theme_options[footer_copyright]', array('type' => 'option', 'default' => $defaults['footer_copyright']));
    $wp_customize->add_control('bigblank_theme_options[footer_copyright]', array('label' => __('Copyright Text', 'bigblank'), 'section' => 'footer', 'settings' => 'bigblank_theme_options[footer_copyright]'));
    // footer text
    $wp_customize->add_setting('bigblank_theme_options[footer_text]', array('type' => 'option', 'default' => $defaults['footer_text']));
    $wp_customize->add_control('bigblank_theme_options[footer_text]', array('label' => __('Footer Text', 'bigblank'), 'section' => 'footer', 'settings' => 'bigblank_theme_options[footer_text]'));
}