$ !gem
gem install benchmark-ips
Fetching benchmark-ips-2.9.1.gem
Successfully installed benchmark-ips-2.9.1
/Users/headius/projects/jruby/lib/ruby/stdlib/rubygems/core_ext/kernel_require.rb:85: warning: parentheses after method name is interpreted as an argument list, not a decomposed argument
Parsing documentation for benchmark-ips-2.9.1
Installing ri documentation for benchmark-ips-2.9.1
Done installing documentation for benchmark-ips after 4 seconds
1 gem installed