'new alternate ids' | 'fdn1' | 'fdn2' | ['other fdn'] || []
'one already used alternate id' | 'fdn1' | 'fdn2' | ['fdn1'] || ['ch-1']
'duplicate alternate id in batch' | 'fdn1' | 'fdn1' | ['dont matter'] || ['ch-2']
'new alternate ids' | 'fdn1' | 'fdn2' | ['other fdn'] || []
'one already used alternate id' | 'fdn1' | 'fdn2' | ['fdn1'] || ['ch-1']
'duplicate alternate id in batch' | 'fdn1' | 'fdn1' | ['dont matter'] || ['ch-2']