eglWaitClient — Complete client API execution prior to subsequent native rendering calls
                EGLBoolean eglWaitClient(
               | 
              void); | 
              
            All rendering calls for the currently bound context, for the
            current rendering API, made prior to
            eglWaitClient are guaranteed to be
            executed before native rendering calls made after
            eglWaitClient. The same result can be
            achieved using client API-specific commands such as
            glFinish
            or
            vgFinish.
        
            eglWaitClient is ignored if there is no
            current EGL rendering context for the current rendering API.
        
            EGL_FALSE is returned if
            eglWaitClient fails,
            EGL_TRUE otherwise.
        
            If there is no current context for the current rendering
            API, the function has no effect but still returns
            EGL_TRUE.
        
            EGL_BAD_CURRENT_SURFACE is generated if
            the surface associated with the current context has a native
            window or pixmap, and that window or pixmap is no longer
            valid.
        
            eglWaitClient is supported only if the
            EGL version is 1.2 or greater.
        
            eglWaitClient is a generalized version
            of eglWaitGL, supporting multiple
            client APIs.
        
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