'Whether this property is read-only.
Read-only properties may only be modified by the client (i.e., by
BokehJS, in the browser). Read only properties are useful for
quantities that originate or that can only be computed in the
browser, for instance the "inner" plot dimension of a plot area,
which depend on the current layout state. It is useful for Python
callbacks to be able to know these values, but they can only be
computed in the actual browser.
Raises:
NotImplementedError
**Subclasses must implement this to serve their specific needs.**'

@property
def readonly(self):

    raise NotImplementedError('Implement    readonly()')
