def current_tenant=(val)
      key = :"roomer_current_tenant"
      unless  Thread.current[key].try(:url_identifier) == val.try(:url_identifier)
        Thread.current[key] = val
        ensure_tenant_model_reset
      end
      Thread.current[key]
    end
def current_tenant=(val)
      key = :"roomer_current_tenant"
      unless  Thread.current[key].try(:url_identifier) == val.try(:url_identifier)
        Thread.current[key] = val
        ensure_tenant_model_reset
      end
      Thread.current[key]
    end
Sets current tenant from ApplicationController into a Thread
 local variable.  Works only with thread-safe Rails as long as
 it gets set on every request
 @return [Symbol] the current tenant key in the thread