Add the optional max_parallelism parameter to the PowerBi class

docs/power_bi/README.md

@@ -267,6 +267,11 @@ The "number_of_retries" parameter only works with enhanced API requests
 be ignored otherwise.
 Default is 0 (no retries). E.g. 1 means two attempts in total.
 
+Additionally, you can set the optional "max_parallelism" parameter to
+set the maximum number of threads that can run processing commands
+in parallel during the refresh in PowerBI. Default is None, which 
+corresponds to 10 threads (according to Microsoft).
+
 All parameters can only be specified in the constructor. 
 
 
@@ -322,6 +327,11 @@ and unlike in the start_refresh() method, it will work both with normal
 refreshes (i.e. when "table_names" is not specified) and with enhanced
 refreshes (i.e. when "table_names" is specified).
 
+Additionally, you can set the optional "max_parallelism" parameter to
+set the maximum number of threads that can run processing commands
+in parallel during the refresh in PowerBI. Default is None, which 
+corresponds to 10 threads (according to Microsoft).
+
 You can also specify the optional "local_timezone_name" parameter to
 show the last refresh time of the PowerBI dataset in a local time zone.
 It is only used for printing timestamps. The default time zone is UTC. 
@@ -421,12 +431,12 @@ OnDemand | The refresh was triggered interactively through the Power BI portal.
 OnDemandTraining | The refresh was triggered interactively through the Power BI portal with automatic aggregations training.
 Scheduled | The refresh was triggered by a dataset refresh schedule setting.
 ViaApi | The refresh was triggered by an API call, e.g. by using this class without the "table_names" parameter specified.
-ViaEnhancedApi | The refresh was triggered by an enhanced API call, e.g. by using this class with the "table_names" parameter specified.
+ViaEnhancedApi | The refresh was triggered by an enhanced API call, e.g. by using this class with the "table_names" or "max_parallelism" parameter specified.
 ViaXmlaEndpoint | The refresh was triggered through Power BI public XMLA endpoint.
 
 Only "ViaApi" and "ViaEnhancedApi" refreshes can be triggered by this class.
 "ViaApi" are refreshes without the "table_names" parameter specified,
-and "ViaEnhancedApi" are refreshes with the "table_names" parameter specified.
+and "ViaEnhancedApi" are refreshes with the "table_names" or "max_parallelism" parameter specified.
 
 To see what tables were specified with each completed refresh marked as
 "ViaEnhancedApi", you can use the show_history_details() and get_history_details()

src/spetlr/power_bi/PowerBi.py

@@ -26,6 +26,7 @@ def __init__(
         max_minutes_after_last_refresh: int = 12 * 60,
         timeout_in_seconds: int = 15 * 60,
         number_of_retries: int = 0,
+        max_parallelism: int = None,
         mail_on_failure: bool = False,
         mail_on_completion: bool = False,
         exclude_creators: List[str] = None,
@@ -60,6 +61,10 @@ def __init__(
             errors when calling refresh() and start_refresh().
             Default is 0 (no retries). (E.g. 1 means two attempts in total.)
             Used only when the timeout_in_seconds parameter allows it!
+        :param int max_parallelism: Specifies the maximum number of threads
+            that can run processing commands in parallel during a refresh
+            in PowerBI. Default is None, which corresponds to 10 threads.
+            Used only with the refresh() and start_refresh() methods!
         :param str local_timezone_name: The timezone to use when parsing
             timestamp columns. The default timezone is UTC.
             If the timezone is UTC, all timestamp columns will have a suffix "Utc".
@@ -94,6 +99,10 @@ def __init__(
                 "The 'number_of_retries' parameter "
                 "must be greater than or equal zero!"
             )
+        if max_parallelism is not None and max_parallelism < 0:
+            raise ValueError(
+                "The 'max_parallelism' parameter must be greater than or equal zero!"
+            )
 
         if (mail_on_failure or mail_on_completion) and table_names is not None:
             raise ValueError(
@@ -110,6 +119,7 @@ def __init__(
         self.max_minutes_after_last_refresh = max_minutes_after_last_refresh
         self.timeout_in_seconds = timeout_in_seconds
         self.number_of_retries = number_of_retries
+        self.max_parallelism = max_parallelism
         self.mail_on_failure = mail_on_failure
         self.mail_on_completion = mail_on_completion
         self.exclude_creators = (
@@ -965,6 +975,9 @@ def _get_refresh_argument_json(
                     "The 'number_of_retries' parameter is ignored in "
                     "start_refresh() if 'table_names' is not specified!"
                 )
+        if self.max_parallelism is not None:
+            result["maxParallelism"] = self.max_parallelism
+
         return result if result else None
 
     def _trigger_new_refresh(self, *, with_wait: bool = True) -> bool: