Sublime Syntax highlight error

$args = array(
    'before_row'        => Core()->helpers->open_grid(), // -> works fine
    'after_row'         => Core()->helpers->close_grid(),
    'after_field'       => array( $this, 'render_after_field' ),
    'attributes'        => array(
        'required'          => 'required',
    ),
);

$args = array(
    'before_row'        => Core()->helpers::open_grid(), // :: in the next line breaks everything
    'after_row'         => Core()->helpers::close_grid(),
    'after_field'       => array( $this, 'render_after_field' ),
    'attributes'        => array(
        'required'          => 'required',
        'data-validation'   => 'token',
    ),
    'classes'           => 'medium-width token large-font has-test-button',
);