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: mod.rs
    path of file: ./repos/solana/sdk/program/src/sysvar
    
    the code of the file until where you have to start completion: //! Access to special accounts with dynamically-updated data.
//!
//! Sysvars are special accounts that contain dynamically-updated data about the
//! network cluster, the blockchain history, and the executing transaction. Each
//! sysvar is defined in its own submodule within this module. The [`clock`],
//! [`epoch_schedule`], [`instructions`], and [`rent`] sysvars are most useful
//! to
    
        fn get() -> Result<Self, ProgramError> {
            let mut var = Self::default();
            let var_addr = &mut var as *mut _ as *mut u8;

            #[cfg(target_os = "solana")]
            let result = unsafe { $crate::syscalls::$syscall_name(var_addr) };

            #[cfg(not(target_os = "solana"))]
            let result = $crate::program_stubs::$syscall_name(var_addr);

            match result {
                $crate::entrypoint::SUCCESS => Ok(var),
                e => Err(e.into()),
            }
        }