def modify_MOLBlock(string):
    """
    Modify Mol block string from KEGG API to have a file source type.

    This means setting line 2 to be '     RDKit          2D'.
    Without this, no chiral information would be collected.

    """
    string = string.split('\n')
    string[1] = '     RDKit          2D'
    string = '\n'.join(string)
    return string