code: def conditions(expressions = {})
        expressions.each do |expression, value|
          if expression == :order
            order value
          elsif expression == :keys
            keys value
          elsif expression == :key
            keys [value]
          elsif expression == :skip
            skip value
          elsif expression == :limit
            limit value
          elsif expression == :include || expression == :includes
            includes(value)
          elsif expression == :cache
            self.cache = value
          elsif expression == :use_master_key
            self.use_master_key = value
          elsif expression == :session
            # you can pass a session token or a Parse::Session
            self.session_token = value
          else
            add_constraint(expression, value)
          end
        end # each
        self #chaining
      end
docs: Constructor method to create a query with constraints for a specific Parse collection.
   Also sets the default limit count to `:max`.
   @overload new(table)
     Create a query for this Parse collection name.
     @example
       Parse::Query.new "_User"
       Parse::Query.new "_Installation", :device_type => 'ios'
     @param table [String] the name of the Parse collection to query. (ex. "_User")
     @param constraints [Hash] a set of query constraints.
   @overload new(parseSubclass)
     Create a query for this Parse model (or anything that responds to {Parse::Object.parse_class}).
     @example
       Parse::Query.new Parse::User
       # assume Post < Parse::Object
       Parse::Query.new Post, like_count.gt => 0
     @param parseSubclass [Parse::Object] the Parse model constant
     @param constraints [Hash] a set of query constraints.
   @return [Query] a new query for the Parse collection with the passed in constraints.
   initialize
   Add a set of query expressions and constraints.
   @example
    query.conditions({:field.gt => value})
   @param expressions [Hash] containing key value pairs of Parse::Operations
     and their value.
   @return [self]