No error thrown with an invalid region

[jamespeapen]

Is there a way to know if the region supplied to the VCF reader is a valid region?

# reading vcf of chr19
reader = VCF("chr19.vcf")

# try getting a region fro chr30 
region = reader("chr30:45407332-45424365")

# use invalid region with letters
region = reader("chr19:45407332-aaaaaaa")

The creation of these invalid regions don't throw any errors. The "no intervals found for vcf" error in thrown only when iterating through the region.

Is there a way to know when an invalid region has been queried without trying to iterate through it?