private function setPrefixes( array $prefixes ) {
		foreach ( $prefixes as $prefix => $iri ) {
			$this->expressionValidator->validate( $prefix, ExpressionValidator::VALIDATE_PREFIX );
			$this->expressionValidator->validate( $iri, ExpressionValidator::VALIDATE_IRI );

			$this->prefixes[$prefix] = $iri;
		}

		$this->usageValidator->trackDefinedPrefixes( array_keys( $this->prefixes ) );
	}