Verify the functionality of the colspan attribute for TD and TH
Test for assertion 11.2.6-7

In the following table, TD is used to specify table cells.

The cell labeled "default" must span one column because no value is specified for the colspan attribute, but 1 is the default value.
The cell labeled "zero" must span THREE COLUMNS because the colspan attribute is set to 0. The 0 value means that the cell spans all columns from the current column to the last column of the column group in which the cell is defined.
The cell labeled "one" must span one column because the colspan attribute is set to 1.
The cell labeled "two" must span two columns because the colspan attribute is set to 2.
The cell labeled "three" must span three columns because the colspan attribute is set to 3.
column 1column 2column 3
default
zero
one
two
three

In the following table, TH is used to specify table cells.

The cell labeled "default" must span one column because no value is specified for the colspan attribute, but 1 is the default value.
The cell labeled "zero" must span THREE COLUMNS because the colspan attribute is set to 0. The 0 value means that the cell spans all columns from the current column to the last column of the column group in which the cell is defined.
The cell labeled "one" must span one column because the colspan attribute is set to 1.
The cell labeled "two" must span two columns because the colspan attribute is set to 2.
The cell labeled "three" must span three columns because the colspan attribute is set to 3.
column 1column 2column 3
default
zero
one
two
three