Parse this person name:

Willem Timmerman, 1774-1850, flourished 1798-1819
user
first_name: Willem
last_name: Timmerman
middle_names: []
temporal:
- start: 1774
  end: 1850
  type: life_span
- start: 1798
  end: 1819
  type: flourished
titles: []
extra_info: []
assistant