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: identity.rs
    path of file: ./repos/rage/age/src
    
    the code of the file until where you have to start completion: use std::fs::File;
use std::io;

use crate::{x25519, Callbacks, DecryptError, EncryptError};

#[cfg(feature = "cli-common")]
use crate::cli_common::file_io::InputReader;

#[cfg(feature = "plugin")]
use crate::plugin;

/// The supported kinds of identities within an [`IdentityFile`].
#[derive(Clone)]
pub enum IdentityFileEntry {
    /// The standard age identity type.
    Native(x25519::Identity),
    /// A plugin-compatible identity.
    #[cfg(feature = "plugin")]
    #[cfg_attr(docsrs, doc(cfg(feature = "plugin")))]
    Plugin(plugin::Identity),
}

impl IdentityFileEntry {
    #[allow(unused_variables)]
    pub(crate) fn into_identity(
        self,
        callbacks: impl Callbacks,
    ) -> Result<Box<dyn crate::Identity>, DecryptError> {
        match self {
            IdentityFileEntry::Native(i) => Ok(Box::new(i)),
            #[cfg(feature = "plugin")]
            IdentityFileEntry::Plugin(i) => Ok(Box::new(crate::plugin::IdentityPluginV1::new(
                i.plugin(),
                &[i.clone()],
                callbacks,
            )?)),
        }
    }

    #[allow(unused_variables)]
    pub(crate) fn to_recipient(
        &self,
        callbacks: impl Callbacks,
    ) -> Result<Box<dyn crate::Recipient + Send>, EncryptError> {
        match self {
            IdentityFileEntry::Native(i) => Ok(Box::new(i.to_public())),
            #[cfg(feature = "plugin")]
            IdentityFileEntry::Plugin(i) => Ok(Box::new(crate::plugin::RecipientPluginV1::new(
                i.plugin(),
                &[],
                &[i.clone()],
                callbacks,
            )?)),
        }
    }
}

/// A list of identities that has been parsed from some input file.
pub struct IdentityF
    
    fn parse_identities<R: io::BufRead>(filename: Option<String>, data: R) -> io::Result<Self> {
        let mut identities = vec![];

        for (line_number, line) in data.lines().enumerate() {
            let line = line?;
            if line.is_empty() || line.starts_with('#') {
                continue;
            }

            if let Ok(identity) = line.parse::<x25519::Identity>() {
                identities.push(IdentityFileEntry::Native(identity));
            } else if let Some(identity) = {
                #[cfg(feature = "plugin")]
                {
                    line.parse::<plugin::Identity>().ok()
                }

                #[cfg(not(feature = "plugin"))]
                None
            } {
                #[cfg(feature = "plugin")]
                {
                    identities.push(IdentityFileEntry::Plugin(identity));
                }

                // Add a binding to provide a type when plugins are disabled.
                #[cfg(not(feature = "plugin"))]
                let _: () = identity;
            } else {
                // Return a line number in place of the line, so we don't leak the file
                // contents in error messages.
                return Err(io::Error::new(
                    io::ErrorKind::InvalidData,
                    if let Some(filename) = filename {
                        format!(
                            "identity file {} contains non-identity data on line {}",
                            filename,
                            line_number + 1
                        )
                    } else {
                        format!(
                            "identity file contains non-identity data on line {}",
                            line_number + 1
                        )
                    },
                ));
            }
        }

        Ok(IdentityFile { identities })
    }