True, if EndOfInput has been reached. After that, Release() is no longer permitted if the buffer contains any content. This property can be set to override this behaviour, but that is an advanced option that should only be exercised if no other option is available.

public virtual bool IsEndOfInput { get; set; }

Public Overridable Property IsEndOfInput As Boolean
	Get
	Set

public:
virtual property bool IsEndOfInput {
	bool get ();
	void set (bool value);
}

abstract IsEndOfInput : bool with get, set
override IsEndOfInput : bool with get, set