function doesn't exists but still runs.....

dear members,
                            I am using the RSelenium package which uses the function selenium() from the wdman package. The selenium function contains the function java_check at line 12. If I try to run it, it throws an error:

  javapath <- java_check()

Error in java_check() : could not find function "java_check"

Also:

exists("java_check")

[1] FALSE

But when I run selenium(), it works fine....

How do you explain this conundrum? You can refer to this link: https://github.com/ropensci/wdman/issues/15

Specifically what concept of R explains this weird behaviour?

Thanking you,
Yours sincerely,
AKSHAY M KULKARNI