source/php/Admin/AdminDisplayEvent.php
public function addMetaBoxes()
    {
        add_meta_box(
            'event-info-box',
            esc_html__('Event', 'event-integration'),
            array($this, 'eventInfo'),
            $this->post_type,
            'normal',
            'high'
        );

        add_meta_box(
            'event-meta-box',
            esc_html__('Meta data', 'event-integration'),
            array($this, 'eventMeta'),
            $this->post_type,
            'normal',
            'low'
        );

        add_meta_box(
            'event-gallery-box',
            esc_html__('Gallery', 'event-integration'),
            array($this, 'eventGallery'),
            $this->post_type,
            'normal',
            'low'
        );

        add_meta_box(
            'event-image-box',
            esc_html__('Featured image', 'event-integration'),
            array($this, 'eventImage'),
            $this->post_type,
            'side',
            'high'
        );

        add_meta_box(
            'event-occasion-box',
            esc_html__('Occasions', 'event-integration'),
            array($this, 'eventOccasions'),
            $this->post_type,
            'side',
            'high'
        );
    }
public function addMetaBoxes()
    {
        add_meta_box(
            'event-info-box',
            esc_html__('Event', 'event-integration'),
            array($this, 'eventInfo'),
            $this->post_type,
            'normal',
            'high'
        );

        add_meta_box(
            'event-meta-box',
            esc_html__('Meta data', 'event-integration'),
            array($this, 'eventMeta'),
            $this->post_type,
            'normal',
            'low'
        );

        add_meta_box(
            'event-gallery-box',
            esc_html__('Gallery', 'event-integration'),
            array($this, 'eventGallery'),
            $this->post_type,
            'normal',
            'low'
        );

        add_meta_box(
            'event-image-box',
            esc_html__('Featured image', 'event-integration'),
            array($this, 'eventImage'),
            $this->post_type,
            'side',
            'high'
        );

        add_meta_box(
            'event-occasion-box',
            esc_html__('Occasions', 'event-integration'),
            array($this, 'eventOccasions'),
            $this->post_type,
            'side',
            'high'
        );
    }
/*
Adding meta boxes to be displayed on the event editor view.