gorm one to many search

问题:

Have the following problem: I have Bookmaker and Users domain classes. And one Bookmaker has many Users.

class Bookmaker {
    ...
    static hasMany = [users: User ...]
    ...
}

And User domain class doesn't contain reference to Bookmaker. My goal is to create method that will return Bookmaker that owns particular User. It looks like:

def lookupBookmaker() {
    User user = User.get(springSecurityService.principal.id)
    def query = Bookmaker.where {
        users.contains(user)
    }
    Bookmaker bookmaker = query.find()
    bookmaker
}

but it doesn't work and gives the following exception:

Class groovy.lang.MissingMethodException Message No signature of method: grails.gorm.DetachedCriteria.contains() is applicable for argument types: (cmscore.User) values: [cmscore.User : 2] Possible solutions: toString(), toString(), notify(), combinations()

and it says that wrong code is this:

users.contains(user)

What I'm doing wrong? Thanks!