Custom world generation/pos rule test


 * ： Root tag.
 * : can be the following values: to always pass;  to pass with a random probability, the probability is based on the 3D Manhattan distance from the current block to the structure start.  to pass with a random probability, the probability only based on the distance on the specified axis.
 * If is, the additional parameters are as follows :
 * : (optional, default is 0.0) The probability (probability less than 0 is treated as 0, greater than 1 is treated as 1) for the predicate to pass when the distance of a block to the structure start is equal to or less than.
 * : (optional, default is 0.0) The probability (probability less than 0 is treated as 0, greater than 1 is treated as 1) for the predicate to pass when the distance of a block to the structure start is equal to or greater than . If a block's distance is between and, probability is obtained by linear interpolation between the values of  and , that is, the probability is , and probability less than 0 is treated as 0, greater than 1 is treated as 1.
 * : (optional, defaults to 0) the distance when the minimum probability is used. Must be less than.
 * : (optional, defaults to 0) the distance when the maximum probability is used. Must be greater than.
 * If is, the additional parameters are as follows :
 * : (optional, defaults to ) can be, or.
 * : (optional, default is 0.0) The probability (probability less than 0 is treated as 0, greater than 1 is treated as 1) for the predicate to pass when the distance of a block to the structure start is equal to or less than.
 * : (optional, default is 0.0) The probability (probability less than 0 is treated as 0, greater than 1 is treated as 1) for the predicate to pass when the distance of a block to the structure start is equal to or greater than . If a block's distance is between and, probability is obtained by linear interpolation between the values of  and , that is, the probability is , and probability less than 0 is treated as 0, greater than 1 is treated as 1.
 * : (optional, defaults to 0) the distance when the minimum probability is used. Must be less than.
 * : (optional, defaults to 0) the distance when the maximum probability is used. Must be greater than.