Function rustfmt_nightly::utils::trim_left_preserve_layout

pub(crate) fn trim_left_preserve_layout(
    orig: &str, 
    indent: Indent, 
    config: &Config
) -> Option<String>

Indent each line according to the specified indent. e.g.

foo!{
x,
y,
foo(
    a,
    b,
    c,
),
}

will become

foo!{
    x,
    y,
    foo(
        a,
        b,
        c,
    ),
}