Struct Document 

pub struct Document {
    pub _file_id: String,
    pub _thumb: Option<PhotoSize>,
    pub _file_name: Option<String>,
    pub _mime_type: Option<String>,
    pub _file_size: Option<i32>,
}

This object represents a general file (as opposed to photos, voice messages and audio files).

Fields

_file_id: String

Unique file identifier

_thumb: Option<PhotoSize>

Optional. Document thumbnail as defined by sender

_file_name: Option<String>

Optional. Original filename as defined by sender

_mime_type: Option<String>

Optional. MIME type of the file as defined by sender

_file_size: Option<i32>

Optional. File size