isAvailable a boolean; verifyAvailable an error message
if RStudio is not running
Arguments
version_needed
An optional version specification. If supplied, ensures
that RStudio is at least that version.
child_ok
Boolean; check if the current R process is a child process of
the main RStudio session? This can be useful for e.g. RStudio Jobs, where
you'd like to communicate back with the main R session from a child process
through rstudioapi.