You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: uuid.rs
    path of file: ./repos/glium/src/context
    
    the code of the file until where you have to start completion: use super::Context;

/// Describes an error preventing the retrieval of the uuid.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum UuidError {
    /// EXT_external_objects is not supported by the driver
    ExtensionNotPresent,
}

impl std::fmt::Display for UuidError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let desc = match self {
            UuidError::ExtensionNotPresent => "EXT_external_objects is not supported by the driver",
        };

        f.write_str(desc)
    }
}

impl std::error::Error for UuidError {}

impl Context {
    /// Returns the UUID of the driver currently being used by this context.
 
    
    pub fn device_uuids(&self) -> Result<Vec<[u8; 16]>, UuidError> {
        if !self.extensions.gl_ext_semaphore && !self.extensions.gl_ext_memory_object {
            return Err(UuidError::ExtensionNotPresent);
        }
        let mut n = std::mem::MaybeUninit::<i32>::uninit();
        let n = unsafe {
            self.gl.GetIntegerv(crate::gl::NUM_DEVICE_UUIDS_EXT, n.as_mut_ptr());
            n.assume_init()
        };

        let mut res = Vec::with_capacity(n as usize);
        for i in 0..n {
            let mut data = [0u8; 16];
            unsafe {
                self.gl.GetUnsignedBytei_vEXT(
                    crate::gl::DEVICE_UUID_EXT,
                    i as u32,
                    data.as_mut_ptr(),
                )
            };
            res.push(data);
        }

        Ok(res)
    }