! @typedef
@abstract Structure for the alignment header.
@field n_targets number of reference sequences
@field l_text length of the plain text in the header
@field target_len lengths of the reference sequences
@field target_name names of the reference sequences
@field text plain text
@field sdict header dictionary
! @typedef @abstract Structure for the alignment header. @field n_targets number of reference sequences @field l_text length of the plain text in the header @field target_len lengths of the reference sequences @field target_name names of the reference sequences @field text plain text @field sdict header dictionary