/// <summary>
/// Initializes a new instance of the <see cref="T:System.Threading.Lazy{T}"/> class
/// that uses a specified initialization function and a specified thread-safety mode.
/// </summary>
/// <param name="valueFactory">
/// The <see cref="T:System.Func{T}"/> invoked to produce the lazily-initialized value when it is needed.
/// </param>
/// <param name="isThreadSafe">true if this instance should be usable by multiple threads concurrently; false if the instance will only be used by one thread at a time.
/// </param>
/// <exception cref="System.ArgumentNullException"><paramref name="valueFactory"/> is
/// a null reference (Nothing in Visual Basic).</exception>
public Lazy(Func <T> valueFactory, bool isThreadSafe) :
this(valueFactory, LazyHelper.GetModeFromIsThreadSafe(isThreadSafe), useDefaultConstructor : false)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="T:System.Threading.Lazy{T}"/>
/// class that uses <typeparamref name="T"/>'s default constructor and a specified thread-safety mode.
/// </summary>
/// <param name="isThreadSafe">true if this instance should be usable by multiple threads concurrently; false if the instance will only be used by one thread at a time.
/// </param>
public Lazy(bool isThreadSafe) :
this(null, LazyHelper.GetModeFromIsThreadSafe(isThreadSafe), useDefaultConstructor : true)
{
}