code: def get_package_info_from_line(tpip_pkg, line):
      
      lower_line = line.lower()
  
      try:
          metadata_key, metadata_value = lower_line.split(':', 1)
      except ValueError:
          return
  
      metadata_key = metadata_key.strip()
      metadata_value = metadata_value.strip()
  
      if metadata_value == 'unknown':
          return
  
      # extract exact matches
      if metadata_key in TPIP_FIELD_MAPPINGS:
          tpip_pkg[TPIP_FIELD_MAPPINGS[metadata_key]] = metadata_value
          return
  
      if metadata_key.startswith('version') and not tpip_pkg.get('PkgVersion'):
          # ... but if not, we'll use whatever we find
          tpip_pkg['PkgVersion'] = metadata_value
          return
  
      # Handle british and american spelling of licence/license
      if 'licen' in lower_line:
          if metadata_key.startswith('classifier') or '::' in metadata_value:
              license = lower_line.rsplit(':')[-1].strip().lower()
              license = license_cleanup(license)
              if license:
                  tpip_pkg.setdefault('PkgLicenses', []).append(license)
docs: Given a line of text from metadata, extract semantic info