Copy the nuget content folder to project output folder

I have created a nuget package with this structure:

NugetName/lib/net/*.dll

NugetName/contentFiles/A/*.dll

NugetName/contentFiles/B/*.dll

> <?xml version="1.0" encoding="utf-8"?> <package> xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">  > <metadata>>     <id>..</id>>     <version>1.0.0.22</version>>     <title>...</title>>     <authors>...</authors>>     <owners>..</owners>>     <requireLicenseAcceptance>false</requireLicenseAcceptance>>     <description>...</description>     >     <contentFiles>>       <files include="contentFiles\A" buildAction="content" copyToOutput="true" flatten="true" />       >       <files include="contentFiles\B" buildAction="content" copyToOutput="true" flatten="true" />>     </contentFiles> >  </metadata> >  <files>>     <file src="Build\Debug\*.dll" target="lib\net\" />>     <file src="Build\Debug\A\*.dll" target="contentFiles\A"  />   >     <file src="Build\Debug\B\*.dll" target="contentFiles\B"  />   >  </files>    > </package>

And now, I need to copy the folders A and B into the project's output folder, but it does not do that!After installing the nuget package, only the NugetName/lib/net/*.dll files are copied, but A and B are not!