return a string describing an EGL display connection
                char const * eglQueryString(
                 | EGLDisplay display, | 
EGLint  name) | 
            
display
                
              
            Specifies the EGL display connection.
name
                
              
            
                        Specifies a symbolic constant, one of
                        EGL_CLIENT_APIS,
                        EGL_VENDOR,
                        EGL_VERSION, or
                        EGL_EXTENSIONS.
                    
            eglQueryString returns a pointer to a
            static string describing an EGL display connection.
            name can be one of the following:
        
EGL_CLIENT_APIS
              
            
                    Returns a string describing which client rendering
                    APIs are supported. The string contains a
                    space-separate list of API names. The list must
                    include at least one of OpenGL,
                    OpenGL_ES, or OpenVG.
                    These strings correspond respectively to values
                    EGL_OPENGL_API,
                    EGL_OPENGL_ES_API, and
                    EGL_OPENVG_API of the
                    eglBindAPI,
                    api argument.
                
EGL_VENDOR
              
            Returns the company responsible for this EGL implementation. This name does not change from release to release.
EGL_VERSION
              
            
                    Returns a version or release number.
                    The EGL_VERSION string is laid out as
                    follows:
                    major_version.minor_version
                    space
                    vendor_specific_info
                
EGL_EXTENSIONS
              
            Returns a space separated list of supported extensions to EGL.
            NULL is returned on failure.
        
            EGL_BAD_DISPLAY is generated if
            display is not an EGL display connection.
        
            EGL_NOT_INITIALIZED is generated if
            display has not been initialized.
        
            EGL_BAD_PARAMETER is generated if
            name is not an accepted value.
        
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