How to create a custom ODATA domain with a simple custom endpoint in Windchill REST Services?

• How to create a custom ODATA domain with a simple custom endpoint?
• How to customize a new REST Service in Windchill for external systems to call?
• How to implement a custom bound function using Windchill REST Service?
• Error occurred performing the custom REST domain: 

Namespace is not allowed for Entity Sets, Singletons, Action Imports and Function Imports; found 'Csutom.Sample'

- ERROR : com.ptc.odata.core.entity.operation.AbstractOperationContainerConfig wcadmin - operation doesn't have binding parameter
Name = SampleSendResponse [ActionPropertyConfig={"name":"SampleSendResponse","description":"SampleSendResponse","parameters":[{"isNullable":false,"name":"PartNumber","isCollection":false,"type":"Strin
g"},{"isNullable":false,"name":"PartName","isCollection":false,"type":"String"}],"returnType":{"isCollection":true,"type":"EntityAttribute"}}]
ERROR : com.ptc.odata.windchill.servlet.WcRestServlet wcadmin - An unexpected REST error occured
The initial segment must not be namespace-qualified.
        at org.apache.olingo.server.core.uri.parser.ResourcePathParser.parsePathSegment(ResourcePathParser.java:86)
        at org.apache.olingo.server.core.uri.parser.Parser.parseUri(Parser.java:234)
        at org.apache.olingo.server.core.ODataHandlerImpl.processInternal(ODataHandlerImpl.java:143)
        at org.apache.olingo.server.core.ODataHandlerImpl.process(ODataHandlerImpl.java:85)
        at org.apache.olingo.server.core.ODataHttpHandlerImpl.process(ODataHttpHandlerImpl.java:74)
        at org.apache.olingo.server.core.LocalODataHttpHandlerImpl.process(LocalODataHttpHandlerImpl.java:24)
        at org.apache.olingo.server.core.ODataHttpHandlerImpl.process(ODataHttpHandlerImpl.java:88)
        at com.ptc.odata.windchill.entity.service.RetryableRequestMediator.process(RetryableRequestMediator.java:476)
        at com.ptc.odata.windchill.servlet.WcRestServlet.service(WcRestServlet.java:167)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:733)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at wt.licenseusage.licensing.LicenseFilter.doFilter(LicenseFilter.java:47)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at com.ptc.jws.servlet.filter.WsdlServletFilter.doFilter(WsdlServletFilter.java:61)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at com.ptc.core.ui.validation.URLValidationFilter.doFilter(URLValidationFilter.java:85)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at wt.httpgw.filter.WTContextBeanFilter.doWithWtContextBeanHandler(WTContextBeanFilter.java:104)