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: arctan.rs
    path of file: ./repos/nushell/crates/nu-cmd-extra/src/extra/math
    
    the code of the file until where you have to start completion: use nu_engine::CallExt;
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, Span, Type, Value};

#[derive(Clone)]
pub struct SubCommand;

impl Command for SubCommand {
    fn name(&self) -> &str {
        "math arctan"
    }

    fn signature(&self) -> Signature {
        Signature::build("math arctan")
            .switch("degrees", "Return degrees instead of radians", Some('d'))
            .input_output_types(vec![
                (Type::Number, Type::Float),
                (
       
    
fn operate(value: Value, head: Span, use_degrees: bool) -> Value {
    match value {
        numeric @ (Value::Int { .. } | Value::Float { .. }) => {
            let span = numeric.span();
            let (val, span) = match numeric {
                Value::Int { val, .. } => (val as f64, span),
                Value::Float { val, .. } => (val, span),
                _ => unreachable!(),
            };

            let val = val.atan();
            let val = if use_degrees { val.to_degrees() } else { val };

            Value::float(val, span)
        }
        Value::Error { .. } => value,
        other => Value::error(
            ShellError::OnlySupportsThisInputType {
                exp_input_type: "numeric".into(),
                wrong_type: other.get_type().to_string(),
                dst_span: head,
                src_span: other.span(),
            },
            head,
        ),
    }
}