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: summary.rs
    path of file: ./repos/nushell/crates/nu-cmd-dataframe/src/dataframe/eager
    
    the code of the file until where you have to start completion: use super::super::values::{Column, NuDataFrame};

use nu_engine::CallExt;
use nu_protocol::{
    ast::Call,
    engine::{Command, EngineState, Stack},
    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
};
use polars::{
    chunked_array::ChunkedArray,
    prelude::{
        AnyValue, DataFrame, DataType, Float64Type, IntoSeries, NewChunkedArray,
        QuantileInterpolOptions, Series, StringType,
    },
};

#[derive(Clone)]
pub struct Summary;

impl Command for Summary {
    fn name(&self) -> &str {
        "dfr summary"
    }

    fn usage(&self) -> &str {
        "For a dataframe, produces descriptive statistics (summary statistics) for its numeric columns."
    }

    fn signature(&self) -> Signature {
        Signature::build(self.name())
            .category(Category::Custom("dataframe".into()))
            .input_output_type(
                Type::Custom("dataframe".into()),
                Type::Custom("dataframe".into()),
            )
            .named(
                "quantiles",
                SyntaxShape::Table(vec![]),
                "provide optional quantiles",
                Some('q'),
            )
    }

    fn examples(&self) -> Vec<Example> {
        vec![Example {
            description: "list dataframe descriptives",
            example: "[[a b]; [1 1] [1 1]] | dfr into-df | dfr summary",
            result: Some(
                NuDataFrame::try_from_columns(
                    vec![
                        Column::new(
                            "descriptor".to_string(),
                            vec![
                                Value::test_string("count"),
                                Value::test_string("sum"),
                                Value::test_string("mean"),
                                Value::test_string("median"),
                                Value::test_string("std"),
                                Value::test_string("min"),
                                Value::test_string("25%"),
                                Value::test_string("50%"),
                                Value::test_string("75%"),
                                Value::test_string("max"),
            
    
    fn examples(&self) -> Vec<Example> {
        vec![Example {
            description: "list dataframe descriptives",
            example: "[[a b]; [1 1] [1 1]] | dfr into-df | dfr summary",
            result: Some(
                NuDataFrame::try_from_columns(
                    vec![
                        Column::new(
                            "descriptor".to_string(),
                            vec![
                                Value::test_string("count"),
                                Value::test_string("sum"),
                                Value::test_string("mean"),
                                Value::test_string("median"),
                                Value::test_string("std"),
                                Value::test_string("min"),
                                Value::test_string("25%"),
                                Value::test_string("50%"),
                                Value::test_string("75%"),
                                Value::test_string("max"),
                            ],
                        ),
                        Column::new(
                            "a (i64)".to_string(),
                            vec![
                                Value::test_float(2.0),
                                Value::test_float(2.0),
                                Value::test_float(1.0),
                                Value::test_float(1.0),
                                Value::test_float(0.0),
                                Value::test_float(1.0),
                                Value::test_float(1.0),
                                Value::test_float(1.0),
                                Value::test_float(1.0),
                                Value::test_float(1.0),
                            ],
                        ),
                        Column::new(
                            "b (i64)".to_string(),
                            vec![
                                Value::test_float(2.0),
                                Value::test_float(2.0),
                                Value::test_float(1.0),
                                Value::test_float(1.0),
                                Value::test_float(0.0),
                                Value::test_float(1.0),
                                Value::test_float(1.0),
                                Value::test_float(1.0),
                                Value::test_float(1.0),
                                Value::test_float(1.0),
                            ],
                        ),
                    ],
                    None,
                )
                .expect("simple df for test should not fail")
                .into_value(Span::test_data()),
            ),
        }]
    }