code: protected function getTableMapping($table)
      {
          if (array_key_exists($table, $this->mappings)) {
              return $this->mappings[$table];
          }
  
          $mapping = $this->retrieveMapping($table);
  
          if (empty($mapping)) {
              throw new \UnderflowException("Table with name {$table} not found.");
          }
  
          $this->mappings[$table] = $mapping;
  
          return $mapping;
      }
docs: Returns table mapping from ordinal field position to associative for all tables.
  
  @param string $table
  
  @return array|bool
  @throws \UnderflowException