class Ransack::Adapters::ActiveRecord::Context

def find_association(name, parent = @base, klass = nil)
  @join_dependency.instance_variable_get(:@join_root).children.detect do |assoc|
    assoc.reflection.name == name && assoc.table &&
    (@associations_pot.empty? || @associations_pot[assoc] == parent || !@associations_pot.key?(assoc)) &&
    (!klass || assoc.reflection.klass == klass)
  end
end