type error in index-api

2019-12-30 12:45:15,242 [qtp1432888450-6253] ERROR (RestXqServlet.java [service]:108) - err:XPTY0004 xs:boolean(true) is not a sub-type of xs:string [at line 166, column 30, source: /db/apps
/SADE/modules/fontane/index-api.xqm]
In function:
        index:get-list-by-id(xs:string) [104:22:/db/apps/SADE/modules/fontane/index-api.xqm]
        index:entites-per-page(xs:string, xs:string) [-1:-1:/db/apps/SADE/modules/fontane/index-api.xqm] 
org.exquery.restxq.RestXqServiceException: err:XPTY0004 xs:boolean(true) is not a sub-type of xs:string [at line 166, column 30, source: /db/apps/SADE/modules/fontane/index-api.xqm]
In function:
        index:get-list-by-id(xs:string) [104:22:/db/apps/SADE/modules/fontane/index-api.xqm]
        index:entites-per-page(xs:string, xs:string) [-1:-1:/db/apps/SADE/modules/fontane/index-api.xqm]
        at org.exist.extensions.exquery.restxq.impl.ResourceFunctionExecutorImpl.execute(ResourceFunctionExecutorImpl.java:197) ~[exist-restxq-4.7.0.jar:4.7.0]
        at org.exquery.restxq.impl.AbstractRestXqService.service(AbstractRestXqService.java:192) ~[exquery-restxq-0.1.34.jar:0.1.34]
        at org.exist.extensions.exquery.restxq.impl.RestXqServiceImpl.service(RestXqServiceImpl.java:124) ~[exist-restxq-4.7.0.jar:4.7.0]
        at org.exist.extensions.exquery.restxq.impl.RestXqServlet.service(RestXqServlet.java:87) [exist-restxq-4.7.0.jar:4.7.0]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) [servlet-api-3.1.jar:3.1.0]

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