code: public int getColumnIndex(String columnName) {
  		Integer index = nameToIndex.get(columnName);
  		if (index == null) {
  			throw new GeoPackageException("Column does not exist in table '"
  					+ tableName + "', column: " + columnName);
  		}
  		return index;
  	}
docs: Get the column index of the column name
  
  @param columnName
  column name
  @return column index