     /// If true, the database is opened readonly.
     public var readonly: Bool
     
-    /// A tracing function that you can use for any purpose.
+    /**
+    An optional tracing function.
+
+    You can use Configuration.logSQL as a tracing function: it logs all SQL
+    statements with NSLog().
+    */
     public var trace: TraceFunction?
+    
+    
+    // MARK: - Initialization
     
     /**
     Setup a configuration.
+    
+    You can use Configuration.logSQL as a tracing function: it logs all SQL
+    statements with NSLog().
     
     - parameter foreignKeysEnabled: If true (the default), the database has
                                     support for foreign keys.

        self.trace = trace
    }
    
    var sqliteOpenFlags: Int32 {
        // See https://www.sqlite.org/c3ref/open.html
        return readonly ? SQLITE_OPEN_READONLY : (SQLITE_OPEN_CREATE | SQLITE_OPEN_READWRITE)

*/
public struct Configuration {
    
    // MARK: - Utilities
    
    /// A tracing function that logs SQL statements
    public static func logSQL(sql: String, bindings: Bindings?) {
        NSLog("GRDB: %@", sql)
