## Privileges required

		if r < 0x20 || r > 0x7d || r == 0x5c {
			if !utf8.ValidRune(r) || (r == utf8.RuneError && size == 1) {
				return false, false
			}
			require = true
		}
	}
	return true, require
}

// prepare performs the bookkeeping operations required at the start of
// CreateHeader and CreateRaw.
func (w *Writer) prepare(fh *FileHeader) error {
	if w.last != nil && !w.last.closed {

    require(keepAliveDuration > 0L) { "keepAliveDuration <= 0: $keepAliveDuration" }
  }

  fun idleConnectionCount(): Int {
    return connections.count {
      it.withLock { it.calls.isEmpty() }
    }
  }

  fun connectionCount(): Int {
    return connections.size
  }

  /**

        val protocolsCopy = protocols.toMutableList()

        // Validate that the list has everything we require and nothing we forbid.
        require(Protocol.H2_PRIOR_KNOWLEDGE in protocolsCopy || HTTP_1_1 in protocolsCopy) {
          "protocols must contain h2_prior_knowledge or http/1.1: $protocolsCopy"
        }
        require(Protocol.H2_PRIOR_KNOWLEDGE !in protocolsCopy || protocolsCopy.size <= 1) {

        }
    }

    private fun KtTypeMappingMode.toTypeMappingMode(
        type: KtType,
        isAnnotationMethod: Boolean,
        suppressWildcards: Boolean?,
    ): TypeMappingMode {
        require(type is KtFirType)
        val expandedType = type.coneType.fullyExpandedType(rootModuleSession)
        return when (this) {
            KtTypeMappingMode.DEFAULT -> TypeMappingMode.DEFAULT

    }
}

private class KtFirResolveExtensionScope(
    private val analysisSession: KtFirAnalysisSession,
    private val tools: List<LLFirResolveExtensionTool>,
) : KtScope {
    init {
        require(tools.isNotEmpty())
    }

    override val token: KtLifetimeToken get() = analysisSession.token

    override fun getCallableSymbols(nameFilter: KtScopeNameFilter): Sequence<KtCallableSymbol> = withValidityAssertion {

                        throw new IllegalStateException(e);
                    }
                }
            }
            throw new IllegalArgumentException("The use of session scoped proxies require "
                    + "a org.eclipse.sisu.Typed or javax.enterprise.inject.Typed annotation");
        }
    }

    /**
     * A provider wrapping an existing provider with a cache

      <fields>
        <field>
          <name>groupId</name>
          <required>true</required>
          <version>1.0.0+</version>
          <type>String</type>
          <description>The group id of the dependency.</description>
        </field>
        <field>
          <name>artifactId</name>
          <required>true</required>
          <version>1.0.0+</version>
          <type>String</type>

        }

        return firLeaf
    }

    private fun computeCommonParent(statements: List<KtElement>): FirElement {
        require(statements.isNotEmpty())

        val parent = statements[0].parent as KtElement

        for (i in 1..<statements.size) {
            require(statements[i].parent == parent)
        }

        val firContainer = collectUseSiteContainers(parent, firResolveSession)?.lastOrNull()

   * explicitly closed.
   */
  fun truncateLastFrame(length: Int): Http2Writer {
    val lastFrame = outFrames.removeAt(outFrames.size - 1)
    require(length < bytesOut.size - lastFrame.start)

    // Move everything from bytesOut into a new buffer.
    val fullBuffer = Buffer()
    bytesOut.read(fullBuffer, bytesOut.size)