def signature_valid?(params)
      params = params.clone
      signature = params.delete(:signature)
      return false unless signature
      Utils.secure_compare(sign_params(params)[:signature], signature)
    end
def signature_valid?(params)
      params = params.clone
      signature = params.delete(:signature)
      return false unless signature
      Utils.secure_compare(sign_params(params)[:signature], signature)
    end
Check if a hash's :signature is valid

 @param [Hash] params the parameters to check
 @return [Boolean] whether or not the signature is valid