The release for this version (e.g. 1.2.0.a -> 1.2.0).
Non-prerelease versions return themselves.
# File lib/rubygems/version.rb, line 303
def release
@release ||= if prerelease?
segments = self.segments
segments.pop while segments.any? { |s| String === s }
self.class.new segments.join('.')
else
self
end
end
