OpenSSL verify certificate from own CA

Hello all and thanks for your time reading this.

I need to verify certificates issued by my own CA, for which I have a
certificate. How can I do the equivalent to openssl’s

openssl verify -CAfile <cafile.pem> <certificate-to-verify.pem>

in Ruby code? The RDoc for OpenSSL is not very helpful in this regard.
I’ve tried:

require 'openssl'

ca ='ca-cert.pem'))

lic ='cert.pem'))

puts lic.verify( ca )

but I get:

test.rb:7:in `verify’: wrong argument (OpenSSL::X509::Certificate)!
(Expected kind of OpenSSL::PKey::PKey) (TypeError)
from test.rb:7

I can’t even find “verify” in the OpenSSL Rdoc at

Any help is appreciated. Thanks again!