 /// - parameter explicitStart: Explicit document start `---`.
 /// - parameter explicitEnd:   Explicit document end `...`.
 /// - parameter version:       YAML version directive.
+/// - parameter sortKeys:      Whether or not to sort Mapping keys in lexicographic order.
 ///
 /// - returns: YAML string.
 ///

/// - parameter explicitStart: Explicit document start `---`.
/// - parameter explicitEnd:   Explicit document end `...`.
/// - parameter version:       YAML version directive.
///
/// - returns: YAML string.
///

/// - parameter explicitStart: Explicit document start `---`.
/// - parameter explicitEnd:   Explicit document end `...`.
/// - parameter version:       YAML version directive.
/// - parameter sortKeys:      Whether or not to sort Mapping keys in lexicographic order.
///
/// - returns: YAML string.
///
