##### The exercice is validated is all questions of the exercice are validated

##### The question 1 is validated if the output is:

    |    |   id | Feature1_x   | Feature2_x   | Feature1_y   | Feature2_y   |
    |---:|-----:|:-------------|:-------------|:-------------|:-------------|
    |  0 |    1 | A            | B            | K            | L            |
    |  1 |    2 | C            | D            | M            | N            |

##### The question 2 is validated if the output is:

    |    |   id | Feature1_df1   | Feature2_df1   | Feature1_df2   | Feature2_df2   |
    |---:|-----:|:---------------|:---------------|:---------------|:---------------|
    |  0 |    1 | A              | B              | K              | L              |
    |  1 |    2 | C              | D              | M              | N              |
    |  2 |    3 | E              | F              | nan            | nan            |
    |  3 |    4 | G              | H              | nan            | nan            |
    |  4 |    5 | I              | J              | nan            | nan            |
    |  5 |    6 | nan            | nan            | O              | P              |
    |  6 |    7 | nan            | nan            | Q              | R              |
    |  7 |    8 | nan            | nan            | S              | T              |

    Note: Check that the suffixes are set using the suffix parameters rather than manually changing the columns' name.