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/vector/src/transforms/dedupe
    
    the code of the file until where you have to start completion: #[cfg(feature = "transforms-dedupe")]
pub mod config;

#[cfg(feature = "transforms-impl-dedupe")]
pub mod transform;

#[cfg(feature = "transforms-impl-dedupe")]
pub mod common {
    use std::num::NonZeroUsize;

    use vector_lib::{configurable::configurable_component, lookup::lookup_v2::ConfigTargetPath};

    use crate::config::log_schema;

    /// Caching configuration 
    
    fn default_match_fields() -> Vec<ConfigTargetPath> {
        let mut fields = Vec::new();
        if let Some(message_key) = log_schema().message_key_target_path() {
            fields.push(ConfigTargetPath(message_key.clone()));
        }
        if let Some(host_key) = log_schema().host_key_target_path() {
            fields.push(ConfigTargetPath(host_key.clone()));
        }
        if let Some(timestamp_key) = log_schema().timestamp_key_target_path() {
            fields.push(ConfigTargetPath(timestamp_key.clone()));
        }
        fields
    }