src/main/php/com-realexpayments-hpp-sdk/domain/HppRequest.php
public function addPayerExists( $payerExists ) {
		if ( is_bool( $payerExists ) ) {
			$this->payerExists = $payerExists ? Flag::TRUE : Flag::FALSE;
		} else {
			$this->payerExists = $payerExists;
		}

		return $this;
	}
public function addPayerExists( $payerExists ) {
		if ( is_bool( $payerExists ) ) {
			$this->payerExists = $payerExists ? Flag::TRUE : Flag::FALSE;
		} else {
			$this->payerExists = $payerExists;
		}

		return $this;
	}
Helper method for adding a payerExists

@param string|bool $payerExists

@return HppRequest