Gets a valid regular expression pattern.
## Static method (use this):
## Arguments$getRegularExpression(pattern=NULL, ..., .name=NULL)## Don't use the below:
# S3 method for Arguments
getRegularExpression(static, pattern=NULL, ..., .name=NULL)
A character
string to be validated.
A character
string for name used in error messages.
Not used.
Returns a character
string.