WordPress at a glance
function is not described

wp_maybe_grant_install_languages_cap() WP 4.9.0

Filters the user capabilities to grant the 'install_languages' capability as necessary.

A user must have at least one out of the 'update_core', 'install_plugins', and 'install_themes' capabilities to qualify for 'install_languages'.

No Hooks.

Return

true/false[]. Filtered array of the user's capabilities.

Usage

wp_maybe_grant_install_languages_cap( $allcaps );
$allcaps(true/false[]) (required)
An array of all the user's capabilities.

Code of wp maybe grant install languages cap: wp-includes/capabilities.php VER 5.1.1

<?php
function wp_maybe_grant_install_languages_cap( $allcaps ) {
	if ( ! empty( $allcaps['update_core'] ) || ! empty( $allcaps['install_plugins'] ) || ! empty( $allcaps['install_themes'] ) ) {
		$allcaps['install_languages'] = true;
	}

	return $allcaps;
}