/// <summary>
/// Determines if the given value represents a valid state of this property.
/// </summary>
/// <param name="value">The state that should be used.</param>
/// <returns>True if the state is valid, otherwise false.</returns>
protected override Boolean IsValid(CSSValue value)
{
var shape = value.ToShape();
if (shape != null)
{
_shape = shape;
}
else if (value.Is(Keywords.Auto))
{
_shape = null;
}
else
{
return(false);
}
return(true);
}