Function diminished_seventh_to_major_tonic 

pub fn diminished_seventh_to_major_tonic(
    possibility: &[Pitch],
    doubled_root: bool,
    info: Option<&ChordInfo>,
) -> Result<Vec<Pitch>>

Resolves a diminished seventh to the major tonic: music21’s diminishedSeventhToMajorTonic. With doubled_root, the third falls to double the tonic rather than rising to its third.

Errors

A possibility that is no fully diminished seventh, when info is not given.