class ActiveRecord::Relation::WhereClause

def equalities(predicates, equality_only)
  equalities = []
  predicates.each do |node|
    if equality_only ? Arel::Nodes::Equality === node : equality_node?(node)
      equalities << node
    elsif node.is_a?(Arel::Nodes::And)
      equalities.concat equalities(node.children, equality_only)
    end
  end
  equalities
end