 /** NormalizationOperation. */
 public struct NormalizationOperation: Codable {
 
-    /// Identifies what type of operation to perform.   **copy** - Copies the value of the `source_field` to the `destination_field` field. If the `destination_field` already exists, then the value of the `source_field` overwrites the original value of the `destination_field`.   **move** - Renames (moves) the `source_field` to the `destination_field`. If the `destination_field` already exists, then the value of the `source_field` overwrites the original value of the `destination_field`. Rename is identical to copy, except that the `source_field` is removed after the value has been copied to the `destination_field` (it is the same as a _copy_ followed by a _remove_).   **merge** - Merges the value of the `source_field` with the value of the `destination_field`. The `destination_field` is converted into an array if it is not already an array, and the value of the `source_field` is appended to the array. This operation removes the `source_field` after the merge. If the `source_field` does not exist in the current document, then the `destination_field` is still converted into an array (if it is not an array already). This is ensures the type for `destination_field` is consistent across all documents.   **remove** - Deletes the `source_field` field. The `destination_field` is ignored for this operation.   **remove_nulls** - Removes all nested null (blank) leif values from the JSON tree. `source_field` and `destination_field` are ignored by this operation because _remove_nulls_ operates on the entire JSON tree. Typically, `remove_nulls` is invoked as the last normalization operation (if it is inoked at all, it can be time-expensive).
+    /// Identifies what type of operation to perform.
+    /// **copy** - Copies the value of the `source_field` to the `destination_field` field. If the `destination_field` already exists, then the value of the `source_field` overwrites the original value of the `destination_field`.
+    /// **move** - Renames (moves) the `source_field` to the `destination_field`. If the `destination_field` already exists, then the value of the `source_field` overwrites the original value of the `destination_field`. Rename is identical to copy, except that the `source_field` is removed after the value has been copied to the `destination_field` (it is the same as a _copy_ followed by a _remove_).
+    /// **merge** - Merges the value of the `source_field` with the value of the `destination_field`. The `destination_field` is converted into an array if it is not already an array, and the value of the `source_field` is appended to the array. This operation removes the `source_field` after the merge. If the `source_field` does not exist in the current document, then the `destination_field` is still converted into an array (if it is not an array already). This is ensures the type for `destination_field` is consistent across all documents.
+    /// **remove** - Deletes the `source_field` field. The `destination_field` is ignored for this operation.
+    /// **remove_nulls** - Removes all nested null (blank) leif values from the JSON tree. `source_field` and `destination_field` are ignored by this operation because _remove_nulls_ operates on the entire JSON tree. Typically, `remove_nulls` is invoked as the last normalization operation (if it is inoked at all, it can be time-expensive).
     public enum Operation: String {
         case copy = "copy"
         case move = "move"

    /**
     Initialize a `NormalizationOperation` with member variables.

     - parameter operation: Identifies what type of operation to perform.   **copy** - Copies the value of the `source_field` to the `destination_field` field. If the `destination_field` already exists, then the value of the `source_field` overwrites the original value of the `destination_field`.   **move** - Renames (moves) the `source_field` to the `destination_field`. If the `destination_field` already exists, then the value of the `source_field` overwrites the original value of the `destination_field`. Rename is identical to copy, except that the `source_field` is removed after the value has been copied to the `destination_field` (it is the same as a _copy_ followed by a _remove_).   **merge** - Merges the value of the `source_field` with the value of the `destination_field`. The `destination_field` is converted into an array if it is not already an array, and the value of the `source_field` is appended to the array. This operation removes the `source_field` after the merge. If the `source_field` does not exist in the current document, then the `destination_field` is still converted into an array (if it is not an array already). This is ensures the type for `destination_field` is consistent across all documents.   **remove** - Deletes the `source_field` field. The `destination_field` is ignored for this operation.   **remove_nulls** - Removes all nested null (blank) leif values from the JSON tree. `source_field` and `destination_field` are ignored by this operation because _remove_nulls_ operates on the entire JSON tree. Typically, `remove_nulls` is invoked as the last normalization operation (if it is inoked at all, it can be time-expensive).
     - parameter sourceField: The source field for the operation.
     - parameter destinationField: The destination field for the operation.


        case removeNulls = "remove_nulls"
    }

    /// Identifies what type of operation to perform.
    /// **copy** - Copies the value of the `source_field` to the `destination_field` field. If the `destination_field` already exists, then the value of the `source_field` overwrites the original value of the `destination_field`.
    /// **move** - Renames (moves) the `source_field` to the `destination_field`. If the `destination_field` already exists, then the value of the `source_field` overwrites the original value of the `destination_field`. Rename is identical to copy, except that the `source_field` is removed after the value has been copied to the `destination_field` (it is the same as a _copy_ followed by a _remove_).
    /// **merge** - Merges the value of the `source_field` with the value of the `destination_field`. The `destination_field` is converted into an array if it is not already an array, and the value of the `source_field` is appended to the array. This operation removes the `source_field` after the merge. If the `source_field` does not exist in the current document, then the `destination_field` is still converted into an array (if it is not an array already). This is ensures the type for `destination_field` is consistent across all documents.
    /// **remove** - Deletes the `source_field` field. The `destination_field` is ignored for this operation.
    /// **remove_nulls** - Removes all nested null (blank) leif values from the JSON tree. `source_field` and `destination_field` are ignored by this operation because _remove_nulls_ operates on the entire JSON tree. Typically, `remove_nulls` is invoked as the last normalization operation (if it is inoked at all, it can be time-expensive).
    public var operation: String?

    /// The source field for the operation.
