The concept class is 'ICD10PCS Hierarchy' for ICD10PCS hierarchy codes and
'ICD10PCS' for concept with the full 7 character code. Since we only
expect to see the complete 7 character ICD10 codes in the source data we
will limit our lookup to where CONCEPT_CLASS = 'ICD10PCS'.
I equate the 'Maps to' relationship with the CDMv4 source to concept map
table. And in that case, I would suggest that the 'Maps to' relationship
for ICD10PCS codes only include a mapping for the 7 character codes i.e.
where concept class = 'ICD10PCS'.