function testKeyOfIndex_SingleKey() {
  var getSchema = function() {
    var tableBuilder = new lf.schema.TableBuilder('Table');
    tableBuilder.
        addColumn('datetime', lf.Type.DATE_TIME).
        addColumn('integer', lf.Type.INTEGER).
        addColumn('number', lf.Type.NUMBER).
        addColumn('string', lf.Type.STRING).
        addIndex('idx_datetime', ['datetime']).
        addIndex('idx_integer', ['integer']).
        addIndex('idx_number', ['number']).
        addIndex('idx_string', ['string']);
    return tableBuilder.getSchema();
  };

  var tableSchema = getSchema();
  var row = tableSchema.createRow({
    'datetime': new Date(999),
    'integer': 2,
    'number': 3,
    'string': 'bar'
  });
  assertEquals(999, row.keyOfIndex('Table.idx_datetime'));
  assertEquals(2, row.keyOfIndex('Table.idx_integer'));
  assertEquals(3, row.keyOfIndex('Table.idx_number'));
  assertEquals('bar', row.keyOfIndex('Table.idx_string'));
  assertEquals(row.id(), row.keyOfIndex('Table.#'));
}
Tests that keyOfIndex() method returns the expected keys, for the case of
single column indices.