private void parseBoundarySpaceDeclaration() throws XPathException {
        if (foundBoundarySpaceDeclaration) {
            grumble("'declare boundary-space' appears more than once", "XQST0068");
        }
        foundBoundarySpaceDeclaration = true;
        nextToken();
        expect(Token.NAME);
        if ("preserve".equals(t.currentTokenValue)) {
            ((QueryModule)env).setPreserveBoundarySpace(true);
        } else if ("strip".equals(t.currentTokenValue)) {
            ((QueryModule)env).setPreserveBoundarySpace(false);
        } else {
            grumble("boundary-space must be 'preserve' or 'strip'");
        }
        nextToken();
    }