translation.xml

<translators default_domain="default">
			<translator domain="default">

				<translator domain="title">
					<message_translator class="AgaviSimpleTranslator">
						<parameter name="fr">
							<parameter name="Where To Buy">Où l'acheter ?</parameter>
						</parameter>
					</message_translator>
				</translator>

				<date_formatter>
					<parameter name="type">date</parameter>
					<parameter name="format">full</parameter>
				</date_formatter>

			</translator>
		</translators>

PHP Code :

		$this->setPageTitle($this->context->getTranslationManager()->_('Where To Buy', 'default.title'));