How can a custom image be used as a bullet on list items?

/* Keyword values */
list-style-image: none;

/* <url> values */
list-style-image: url('starsolid.gif');

/* valid image values */
list-style-image: linear-gradient(to left bottom, red, blue);

/* Global values */
list-style-image: inherit;
list-style-image: initial;
list-style-image: unset;