fdbcli flags currently contain a mixture of _ and - (probably for historic reasons). I would propose to unify the flags and only use either _ or - personally I tend to hyphens like recommended in the POSXI standard (https://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html). Current fdbcli help output:

FoundationDB CLI 6.2 (v6.2.29)
usage: /usr/bin/fdb/6.2/fdbcli

• Delta Lake 1.0.0
• Spark 3.1.2
• Scala 2.12
• AdoptOpenJDK-11.0.11+9 (build 11.0.11+9)

The following code gives a NullPointerException. This is for a directory-based delta table that does not exist and uses a generated column.

import io.delta.tables.DeltaTable
DeltaTable.create
  .addColumn(
    DeltaTable.columnBuilder("value")
      .generatedAlwaysAs("true")
      .nullab

Satisfies and 3.6.1 and 3.7.1