method_exists? is missing?

In a controller run through webrick I do this:

@entity = Entity.new
print @entity.methods.sort.to_yaml

and I see this:

- logger
- mark_for_destruction
- marked_for_destruction?
- metaclass
- method
- method_missing
- methods
- new_record?

There is no method_exists? method. If I instead do this in a console
session, I see this:

$ script/console

@entity = Entity.new

=> ...

print @entity.methods.sort.to_yaml

...
- logger
- mark_for_destruction
- marked_for_destruction?
- metaclass
- method
- method_exists?
- method_missing
- methods
- mocha
- mocha_inspect
- new_record?
...

However, if I remove the mocha gem (0.9.5) then method_exists?
disappears from Entities created in the console as well.

So, what gives?

James Byrne wrote:

So, what gives?

Turns out I should be using #respond-_to? instead. Method_missing? is
part of mocha.