WP_Icons_Registry::register( string $icon_name, array $icon_properties ): bool

63	public function register( $icon_name, $icon_properties ) {64		if ( ! isset( $icon_name ) || ! is_string( $icon_name ) ) {65			_doing_it_wrong(66				__METHOD__,67				__( 'Icon name must be a string.' ),68				'7.0.0'69			);70			return false;71		}72 73		// Require a namespaced name in the form "collection/icon-name".74		if ( ! str_contains( $icon_name, '/' ) ) {75			_doing_it_wrong(76				__METHOD__,77				__( 'Icon name must be namespaced in the form "collection/icon-name".' ),78				'7.1.0'79			);80			return false;81		}82 83		// Split the namespaced name into a collection slug and an unqualified icon name.84		list( $collection, $unqualified_name ) = explode( '/', $icon_name, 2 );85 86		if ( preg_match( '/[A-Z]/', $unqualified_name ) ) {87			_doing_it_wrong(88				__METHOD__,89				__( 'Icon names must not contain uppercase characters.' ),90				'7.1.0'91			);92			return false;93		}94 95		if ( ! preg_match( '/^[a-z0-9](?:[a-z0-9_-]*[a-z0-9])?$/', $unqualified_name ) ) {96			_doing_it_wrong(97				__METHOD__,98				__( 'Icon names must start and end with a lowercase letter or digit and contain only lowercase letters, digits, hyphens, and underscores.' ),99				'7.1.0'100			);101			return false;102		}103 104		$allowed_keys = array_fill_keys( array( 'label', 'content', 'file_path' ), 1 );105		foreach ( array_keys( $icon_properties ) as $key ) {106			if ( ! array_key_exists( $key, $allowed_keys ) ) {107				_doing_it_wrong(108					__METHOD__,109					sprintf(110						/* translators: %s: The name of a user-provided key. */111						__( 'Invalid icon property: "%s".' ),112						$key113					),114					'7.0.0'115				);116				return false;117			}118		}119 120		if ( ! WP_Icon_Collections_Registry::get_instance()->is_registered( $collection ) ) {121			_doing_it_wrong(122				__METHOD__,123				sprintf(124					/* translators: %s: Icon collection slug. */125					__( 'Icon collection "%s" is not registered.' ),126					$collection127				),128				'7.1.0'129			);130			return false;131		}132 133		if ( ! isset( $icon_properties['label'] ) || ! is_string( $icon_properties['label'] ) ) {134			_doing_it_wrong(135				__METHOD__,136				__( 'Icon label must be a string.' ),137				'7.0.0'138			);139			return false;140		}141 142		if (