code: public void addFieldQueryMust(String fieldName, String searchQuery) {
  
          addFieldQuery(fieldName, searchQuery, BooleanClause.Occur.MUST);
      }
docs: Adds an individual query for a search field that MUST occur.<p>
  
  If this is used, any setting made with {@link #setQuery(String)} and {@link #setField(String[])}
  will be ignored and only the individual field search settings will be used.<p>
  
  When combining occurrences of SHOULD, MUST and MUST_NOT, keep the following in mind:
  All SHOULD clauses will be grouped and wrapped in one query,
  all MUST and MUST_NOT clauses will be grouped in another query.
  This means that at least one of the terms which are given as a SHOULD query must occur in the
  search result.<p>
  
  @param fieldName the field name
  @param searchQuery the search query
  
  @since 7.5.1