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: go_fmph.rs
    path of file: ./repos/reth/crates/storage/nippy-jar/src/phf
    
    the code of the file until where you have to start completion: use crate::{NippyJarError, PHFKey, PerfectHashingFunction};
use ph::fmph::{GOBuildConf, GOFunction};
use serde::{
    de::Error as DeSerdeError, ser::Error as SerdeError, Deserialize, Deserializer, Serialize,
    Serializer,
};

/// Wrapper struct for [`GOFunction`]. Implementation of the following [paper](https://dl.acm.org/doi/10.1145/3596453).
#[derive(Default)]
pub struct GoFmph {
    function: Option<GOFunction>,
}

impl GoFmph {
    pub fn new() -> Self {
        Self { function: None }
    }
}

impl PerfectHashingFunction for GoFmph {
    fn set_keys<T: PHFKey>(&mut self, keys: &[T]) -> Result<(), NippyJar
    
    fn eq(&self, other: &Self) -> bool {
        match (&self.function, &other.function) {
            (Some(func1), Some(func2)) => {
                func1.level_sizes() == func2.level_sizes() &&
                    func1.write_bytes() == func2.write_bytes() &&
                    {
                        let mut f1 = Vec::with_capacity(func1.write_bytes());
                        func1.write(&mut f1).expect("enough capacity");

                        let mut f2 = Vec::with_capacity(func2.write_bytes());
                        func2.write(&mut f2).expect("enough capacity");

                        f1 == f2
                    }
            }
            (None, None) => true,
            _ => false,
        }
    }