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: dart.rs
    path of file: ./repos/zed/crates/languages/src
    
    the code of the file until where you have to start completion: use anyhow::{anyhow, Result};
use async_trait::async_trait;
use gpui::AppContext;
use language::{LanguageServerName, LspAdapter, LspAdapterDelegate};
use lsp::LanguageServerBinary;
use project::project_settings::ProjectSettings;
use serde_json::Value;
use settings::Settin
    
    fn workspace_configuration(&self, _workspace_root: &Path, cx: &mut AppContext) -> Value {
        let settings = ProjectSettings::get_global(cx)
            .lsp
            .get("dart")
            .and_then(|s| s.settings.clone())
            .unwrap_or_default();

        serde_json::json!({
            "dart": settings
        })
    }