Because BlockLabels uses _lines instead of _title, set_title does nothing.

To reproduce:

import py_cui
root = py_cui.PyCUI(2,2)
root.set_title('Block Labels')
label = root.add_block_label('Hello\nWorld', 0,0, row_span=2, column_span=2)
label.set_title('Goodbye\nWorld')
root.start()

Expected behavior
set_title(title) should set the BlockLabel's ._lines attribute to title.splitlines(), or an alternative function should be supplied to set the lines attribute directly.

Environment:

• OS: Windows 10
• Terminal: Powershell Core
• Version: 0.1.1