invoke
Operator function to create a new instance of StrokeJoin. Converts the first character of the given string parameter to uppercase, then returns a StrokeJoin instance with this new string.
If the provided value is null, this function likewise returns null.
Return
A new StrokeJoin object, or null if the input string was null.
Parameters
value
A nullable string which will represent the stroke cap. This string, if provided, will have its first character converted to uppercase.