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: window_geometry.rs
    path of file: ./repos/eww/crates/yuck/src/config
    
    the code of the file until where you have to start completion: use std::collections::HashMap;

use crate::{
    enum_parse,
    error::DiagResult,
    format_diagnostic::ToDiagnostic,
    parser::{ast::Ast, ast_iterator::AstIterator, from_ast::FromAstElementContent},
    value::{coords, Coords, NumWithUnit},
};

use super::window_definition::EnumParseError;
use eww_shared_util::{Span, VarName};
use serde::{Deserialize, Serialize};
use simplexpr::{
    dynval
    
    fn from_tail<I: Iterator<Item = Ast>>(_span: Span, mut iter: AstIterator<I>) -> DiagResult<Self> {
        let mut attrs = iter.expect_key_values()?;
        iter.expect_done()
            .map_err(|e| e.to_diagnostic().with_notes(vec!["Check if you are missing a colon in front of a key".to_string()]))?;

        Ok(WindowGeometryDef {
            anchor_point: attrs.ast_optional("anchor")?,
            size: CoordsDef { x: attrs.ast_optional("width")?, y: attrs.ast_optional("height")? },
            offset: CoordsDef { x: attrs.ast_optional("x")?, y: attrs.ast_optional("y")? },
        })
    }