Function command_body 

pub fn command_body<'i, Input, Error>(
    input: &mut Input,
    kind: CommandKind,
) -> Result<Command, Error>
where
    Input: StreamIsPartial + Stream + Compare<&'i str>,
    <Input as Stream>::Slice: AsBStr,
    <Input as Stream>::Token: AsChar + Clone,
    Error: ParserError<Input>,

Parse the body of a command after count( or union( has been consumed.

Grammar: [DISTINCT] [ALL] [columns OF] source1[, source2, ...] )