wp-includes/class-wp-icons-registry.php:225Retrieves the content of a registered icon.
$icon_namestringstring|null protected function get_content( $icon_name ) { if ( ! isset( $this->registered_icons[ $icon_name ]['content'] ) ) { $content = file_get_contents( $this->registered_icons[ $icon_name ]['filePath'] ); $content = $this->sanitize_icon_content( $content ); if ( empty( $content ) ) { wp_trigger_error( __METHOD__, __( 'Icon content does not contain valid SVG markup.' ) ); return null; } $this->registered_icons[ $icon_name ]['content'] = $content; } return $this->registered_icons[ $icon_name ]['content']; }Unchanged from 7.0.4 through 7.1.0.
Signature, return type and hooks compared across 2 parsed releases.
src/wp-includes/class-wp-icons-registry.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.